下列关于tRNA的叙述错误的是（）A.5’-末端为C-C-A B.tRNA分子中含较

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问题单项选择题

下列关于tRNA的叙述错误的是（）

A.5’-末端为C-C-A

B.tRNA分子中含较多稀有碱基

C.tRNA的二级结构通常是三叶草形

D.在RNA中它是最小的单链分子

答案

参考答案：A

听力题

根据句意，用括号中所给单词的正确形式填空。

小题1:Thursday is the (five) day of the week.

小题2:John’s aunt felt even ______(bad). She had to see a doctor again.

小题3:Jake asked me where (buy) the book.

小题4:When I see our (nation) flag, I feel very proud of our country.

小题5:It is ________(terrible) cold today. You should put on more clothes.

小题6:-----What were the twins doing when the telephone rang?

-----They _____________ (prepare) for tomorrow’s party.

小题7:Mother is busy __________ (cook) for the coming big dinner in the kitchen.

单项选择题

主动脉关闭不全的杂音传导方向是（）

A．向颈部传导

B．向心底部传导

C．向心尖部传导

D．向左腋下部传导

E．向剑突下传导