49. In group discussions, what behavior do professors consider acceptable?
(A)Interruption
(B) Quietness
(C) Rudeness
(D) Talking on the cell phone

45. (A)call (B)called (C)calling (D)to call

46. What is the main point of this passage? (A)Understanding professors' questions is important. (B) Behaving oneself is important. (C) Participation in class is important. (D) Being polite in college is important.

47. How long does a professor usually wait for the student's answer? (A)Less than 10 seconds. (B) Between 30 to 60 seconds. (C) About two minutes. (D) Long enough for the student to come up with good answers.

48. What is Not a professor's expectation of his or her students? (A) Attending class. (B) Being polite in group discussions. (C) Sharing personal experience. (D) Expressing agreements with everything

50. Which following statement about college students is true? (A)They are free to skip classes. (B) They are usually punished for talking in class. (C) Their professors get angry if the students do not know the answers. (D) Their professors encourage them to express their opinions.

1.生物膜将真核细胞分隔成不同的区室，使得细胞内能够同时进行多种化学反应，而不会相互干扰。下列叙述正确的是  (A).细胞核是mRNA合成和加工的场所         (B).高尔基体是肽链合成和加工的场所   (C).线粒体将葡萄糖氧化分解成CO2和H2O     (D).溶酶体合成和分泌多种酸性水解酶

2细胞代谢受酶的调节和控制。下列叙述正确的是   (A).激素都是通过影响靶细胞内酶活性来调节细胞代谢  (B).代谢的终产物可反馈调节相关酶活性，进而调节代谢速率   (C).同一个体各种体细胞酶的种类相同、数量不同，代谢不同   (D).对于一个细胞来说，酶的种类和数量不会发生变化

3.右图为每10粒水稻种子在成熟过程中干物质和唿吸速率 变化的示意图。下列分析不正确的是   (A).种子干物质快速积累时期，唿吸作用旺盛   (B).种子成熟后期自由水减少，唿吸速率下降   (C).种子成熟后期脱落酸含量较高，唿吸速率下降   (D).种子唿吸速率下降有利于干物质合成

4.下列现象中，与减数分裂同源染色体联会行为均有关的是  ①人类的47，XYY综合征个体的形成      ②线粒体DNA突变会导致在培养大菌落酵母菌时出现少数小菌落      ③三倍体西瓜植株的高度不育      ④一对等位基因杂合子的自交后代出现3：1的性状分离比 ⑤卵裂时个别细胞本牲体异常分离，奖形成人类的21三体综合征个体   (A)．①②          (B).．①⑤          (C)．③④            (D)．④⑤

5.科学家温特做了如下实验：把切下的燕麦尖端放在琼脂块上，几小时后，移去胚芽鞘尖端，将琼脂块切成小块。再将经处理过的琼脂块放在切去尖端的燕麦胚芽鞘一侧，结果胚芽鞘会朝对侧弯曲生长。但是，如果放上的是没有接触过胚芽鞘尖端的琼脂块，胚芽鞘则既不生长也不弯曲。该实验证明了   (A)生长素只能从形态学上端运输到形态学下端      (B).造成胚芽鞘弯曲的刺激是某种化学物质   (C).生长素的化学本质是吲哚乙酸                  (D).胚芽鞘会弯向光源生长