问题
单项选择题 A1型题
体内一碳单位的运载体是()
A.叶酸
B.维生素B12
C.四氢叶酸
D.二氢叶酸
E.生物素
答案
参考答案:C
体内一碳单位的运载体是()
A.叶酸
B.维生素B12
C.四氢叶酸
D.二氢叶酸
E.生物素
参考答案:C
第二节选词填空(共10小题;每小题1分,满分10分) 根据句意,选择适当的词并用其恰当的形式填空。
67. Their _____ came from China. They are always dreaming of coming back to their motherland some day. 68. With combined effort, we are sure to find a _____ to the problem. 69. The weather this week is really _____; the sun never shows up and it is very windy sometimes. 70. I finally _____ him of my innocence. 71. Although he enjoyed great _____, he is never too proud of himself. 72. 20% of the population live below the _____ line while many live a luxurious(奢华的) life. 73. It is impolite of you to speak to him that way. You should _____ to him. 74. The lecture on “How to learn English Words” _____ many students. 75. The government intends to move out the factories that _____ the air and water. |