1. Xiao Tao pays great attention to eye hygiene. After reading for a while, he looks away. From reading to viewing, the changes in Xiaotao's pupils and lens are: ( )
A. Enlargement and increased curvature B. Narrowing and increased curvature
C. Enlargement and curvature. Reduce D, shrink and reduce curvature
2. When an electric eel catches prey, it discharges electricity at a very high frequency. The same type of electric eel will hear the news and use its “language”. to communicate information. Yes ( ) A. Action B. Current C. Sound D. Smell
3. Most fish can lay eggs in quantities ranging from tens of thousands to millions, but the mortality rate of fry is very high. high, so the number of adult fish is very low. The phenomenon of high spawning volume of these fish is ( )
A. An adaptation B. Relativity of adaptation
C. The result of genetics and long-term variation D. The result of restriction by abiotic factors
4. To test whether green plants release carbon dioxide during respiration, the necessary experimental conditions are ( )
A. Use a plant with many leaves B. Submerge the plant in water
C. Experiment in dark conditions D. Use a young plant
5. Organ transplantation Success. is a great achievement of human medicine, because organs transplanted into the human body have difficulty surviving. According to the concept of modern immunology, tissue cells implanted in an organ are equivalent to ( )
A. Tumor cells B. Damaged cells C. Antibodies D. Antigen
6 . Various antibiotics play an important role in the treatment of diseases caused by bacterial infections. However, after a certainmps of use of antibiotics, the bactericidal effect will decrease. Explained by Darwin's evolutionary perspective, the reason is ( )
A. The selective effect of antibiotics on bacteria B. The selection effect of bacteria on antibiotics
C. Product quality declines D. Physical decline of human beings
7. Among the following, the one that cannot be used as an example of variation is ( )
A. Sheep have horns, horses do not have horns. B. Cows have high milk production, animals have low milk production
C. Human ears have earlobes and do not have them D. The vision of a person goes from normal to myopia
8. the first of the following is a mollusk and the second Which annelid is ( )
A. Scallop, hydra B. Squid, leech C. Earthworm, snail D. River mussel, centipede< /p>
9. After gas exchange in the tissues, the bloodcirculating through the tissues becomes
A. Arterial blood containing more oxygen and less carbon dioxide B. Arterial blood containing more oxygen and less carbon dioxide More arterial blood< /p>
C. Venous blood containing less oxygen and more carbon dioxide D. Venous blood containing less oxygen and less carbon dioxide
10 In order to prove a certain point, scientists. The following two experiments were successively carried out: ① The thyroid gland of the tadpoles was destroyed, and it was found that the tadpoles stopped developing and could not develop into adult frogs ② Thyroid hormone was put in the water of the breeding tank, and the tadpoles that destroyed the thyroid gland transformed into adult frogs. These two experiments can prove ( )
A. The thyroid gland can secrete thyroid hormone B. Thyroid hormone can promote dedevelopment of young animals
C. Growth hormone can promote the growth of tadpoles D. A and B
Answers
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< h3>What should I prepare for my first camping trip?| Analysis of test questions: (1) ① Fossil fuels refer to coal and oil. , Natural gas is a non-renewable energy source. ②The main component of natural gas is methane. Methane burns to produce carbon dioxide and water. The equation is CH 4 +2O 2 2H 2 O+CO 2 . (2) Other new energy sources that people use and develop, such as solar energyenergy, nuclear energy, wind energy, geothermal energy and tidal energy, etc. (3) ① Based on the actual service life, it can be seen that the material with good thermal conductivity is metal, so item A is correct. ②The outer flame has the highest temperature, so use the outer flame when heating. ③ If the “stove” is filled with dead branches, it will not burn well and will produce a lot of thick smoke, indicating insufficient combustion and a lack of oxygen. |
Tent: A tent is a necessary item for camping Since the tent directly affects the quality of sleep, you can choose it according to the . outdoor location and seasonal changes. A suitable tent.
Medication: As there will be many insects and ants when wild camping, medicine is an essential item. Before leaving, plan the locationspossible situations to prepare for.
Moisture-proof mat or air mattress: When camping in the wild, the ground will be relatively damp. There are physical moisture-proof mats or inflatable sleeping mats available on the market. Buy it, it can effectively isolate ground moisture, maintain body temperature and sleep quality.
Backpack: You can choose a backpack with appropriate specifications depending on the number of days you will be camping. Backpacks are often the most suitable bags for outdoor camping sites. They are not only practical, but also have a large capacity. . It is recommended to choose a separate backpack so that you can place the necessary items by categories.