73．Very few species depend entirely on genetic learning because .
(A)．each generation has its own way of learning
(B)．their environments change all the time
(C)．they can act reasonably on their own
(D)．it takes their whole life to learn

69．From the passage we know “robotic vehicles” are a kind of machines that . (A)．can do effortlessly whatever tasks living thing can (B)．can take part in a race across 142 miles with a time limit (C)．can show off their ability to turn themselves upside down (D)．can move from place to place without being driven by human beings

70．In the race , the greatest distance one robotic vehicle covered was . (A)．about eight miles (B)．six miles (C)．almost two miles (D)．about one mile

71．In the last paragraph , the writer implies that there is a long way to go . (A)．for a robotic vehicle to finish a 142-mile race without any difficulties (B)．for a little child who has just learned to walk to reach the cookie on the table (C)．for a robotic vehicle to deal with a simple problem that a little child can solve (D)．for a little child to understand the importance of wiping apple juice off its face

72．The animal’s life will come to an end . (A)．if the animal makes a wrong decision (B)．if the animal plays a dangerous game (C)．when the animal attacks its enemy (D)．when the animal runs too slowly

74．When the environment doesn’t change much , . (A)．animals cannot act in a right way (B)．genetic learning is less important for animals (C)．individual learning plays a less important role (D)．animals cannot get over problems on their on their own

75．Animals’ living on generation after generation depends on . (A)．their natural action pattern with their own experience (B)．the lessons they have learnt during their lifetime (C)．their experience in particular environments (D)．the knowledge passed on by their parents

21. To make members Of a team perform better, the trainer first of all has to know their _____ and weaknesses. (A). strengths (B). benefits (C). techniques (D). values

22. One of the best ways for people to keep fit is to______ healthy eating habits. (A). grow (B) develop (C). increase (D). raise

23. The ______on his face told me that he was angry. (A). impression (B). sight (C). appearance (D). expression

24. At tile meeting they discussed three different ______to the study of mathematics. (A). approaches (B). means (C). methods (D). ways