The national decision is based on each middle school, and each middle school organizes its own team to go to the examination room according to the schedule. The next day, Lan Jie went to the magic capital with the sheep middle school competition team. Before the start of the competition, Lei Tiangang's coaching team led the players to familiarize themselves with the examination room of Jiaotong University.

The examination rooms all over the world are almost the same, and Lan Jie and they are familiar with it at once.

"Since you have come to Jiaotong University, you must learn from the glorious deeds of Mr. Qian Xuesen. "Ranger made his request.

Lei Tiangang made an arrangement: "There are many visitors to Qian Xuesen Library, and under the leadership of the coach, you will study in batches." ”

"Yes, yes!"

"Go, go, go!"

The enthusiasm of the students and competition team members in the sheep was high, and everyone went to the Qian Xuesen Library in batches to actively learn the glorious history of Qian's predecessors.

"I will do my best to build my country together with the Chinese people, so that my compatriots can live a dignified and happy life." "--- Qian Xuesen.

Qian Xuesen's simple, sincere, and sonorous words will always remain in the most eye-catching position of Qian Xuesen Library.

Lan Jie had already learned Qian Lao's words, and if he learned it again today, his blood was boiling.

Academic rigor, engineering innovation, the heart of the motherland, and with practical actions to practice feelings, with master professional technology to serve the motherland...... Qian Lao's great achievements and bits and pieces of life, Lan Jie's young people learn 10,000 times.

Lan Jie stood in front of Qian Xuesen's huge photo and muttered to himself: "Old Qian, your physics problems are super difficult, I can't understand them at all, let alone solve them." ”

"Mr. Qian, you are one of my most respected scientists, learn from you! I also hope that you can bless me to be invincible on the road of my studies and soar to the sky on the future academic road!"

Lan Jie stayed in Qian Xuesen's library for a long time, and he studied Qian Xuesen's academic manuscripts one symbol at a time.

These academic manuscripts were written by Qian Xuesen in his golden period of scholarship, and Lan Jie certainly did not understand them.

Set yourself a small goal first.

Lan Jie's small goal is to try to understand Qian Xuesen's aerodynamic theory and rocket design draft as soon as possible.

"Students, it is a necessary activity to learn Qian Xuesen, but you should not be too relaxed, please remember that you are here to participate in the biology competition. The coach of the Yang Zhongsheng competition team reminded him, and the coach saw that the time was almost up, closed the team, and went back to the dormitory.

Nothing was said all night. Early the next morning, Ranger woke up at five o'clock as usual.

Coming to the national finals for the first time, Lan Jie was both impulsive and a little nervous.

At half past eight, the theory test of the national decision of the students began.

This theory paper has ten questions with a total of 100 marks, and the exam time is four hours.

There are no multiple-choice, fill-in-the-blank, true/false, all calculation questions and short-answer questions.

Langer skimmed through the exam papers and answered them immediately.

In the first question, students are invited to read a piece of material.

H. Bänziger had observed the blood-sucking of buffalo blood by the vampire moth (Calpe eustrigata) in Malaysia, and he thought that the vampire moth was only feeding on the blood droplets of mammals when they were bitten by mosquitoes, but when he cut his finger and exposed it to the vampire moth, he found that although the vampire moth dipped its snout in the blood droplet, it did not suck the blood exposed to the surface, but pierced the tender flesh of the wound and sucked the blood in H. Bänziger's body.

Among the more than 200,000 species of lepidopteran insects, there are only four moths with blood-sucking behavior. It is an extremely rare behavior for moths to suck blood, so please explain why moths suck blood according to your understanding. (ten minutes)

Lan Jie fell into deep thought, but all the players who advanced to the national finals should be able to guess that the vampire moth sucks blood in order to obtain richer nutrition, to be specific, blood sucking is to get more and better quality sodium.

But just write such a sentence, at most you will get one or two points, and it will definitely not exceed three points.

If you want to get a full score for this question, you have to give a set of self-justifying explanations and strive to achieve self-consistency in the question.

Mr. Lei has said more than once that there are many strange biological phenomena in nature that lack fossil evidence, so it is difficult for scientists to give a clear conclusion. But that doesn't stop us from making bold and reasonable guesses, and this type of question is open-ended.

In the absence of fossil evidence, studies are mainly carried out by comparative behavioral studies of extant species.

Ranger made a bold guess and a reasonable guess, and he wrote on the test paper:

As far as I know, the vast majority of moths have siphon mouthparts, which feed on nectar from flowers to replenish sugar. At the same time, these moths also feed on urine, sweat, and tears excreted by humans and animals to replenish sodium.

In the long process of evolution, the snout of a few moths has undergone great changes in structure and function (evolution), in addition to the standard siphon, there is also a drill bit, which is very hard, and some have a small number of short bristles at the end, which has the function of a file.

This kind of drill + file kiss can pierce fruits with thick skin, which is quite powerful!

If a moth's snout has the ability to pierce the peel of an orange, then it also has the ability to pierce the skin of a mammal and suck blood.

So my surmised evolutionary route is: excrement-sucking moths→ fruit moths→ vampire moths!

The following is a simplified diagram of the evolutionary stages of the vampire moth......

After completing the first question, Lan Jie couldn't help but sigh, nature is so wonderful!

"There are many mysteries of nature that have not yet been studied by humans, and we humans must be in awe of nature before we can decipher them. ”

This sentence was written on the scroll by Lan Jie, and it was bold and black.

After watching the documentary, he would look up relevant professional literature to conduct more in-depth study.

has been prostituting a certain B family for so many years, and has been prostituting until the finals of the Shengjing country, Lan Jie feels that it is very cost-effective, and he will continue to prostitute for nothing in the future.

Calculation questions are relatively boring, and calculation questions do not test imagination, but test the depth of knowledge and computing ability.

The fifth question is a calculation question. It is said that the most cost-effective way to control mosquitoes is to change the entire aquatic community, not poison them. In the same way, the protection and development of a certain organism must first protect and develop the community and suitable environment with which it coexists.

This involves the calculation of the diversity of species in the community.

Ranger fully understood the meaning of the question, and based on the Simpson model, he made the following calculation: D=1/∑i=1(ni/N)^2......

D1=0.0198 and D2=0.5.

'it!'

'Another problem!'

'It's not difficult to compete in the theory of national decision!'

'Just be careful and use your imagination properly, and you'll be fine!'

'Last question, please design an experimental ......'

'This experimental design question is very difficult!'

Lan Jie rubbed his temples, time was running out for him, he had to devise a theoretically feasible biological experiment as soon as possible.