与tRNA反密码子CAG配对的mRNA密码子是()
A.GUC
B.CUG
C.CTG
D.GTC
E.GAC
参考答案:B
如图所示,电压U保持不变,当开关断开时,R1消耗的电功率为P1,当开关闭合时R1消耗的电功率P1',则
A.P'=P1
B.P1'>P1
C.P1'<P1
D. 无法比较
Many questions __________ at the meeting, but he answered none.
A.came up
B.raised
C.were risen
D.asked