When ________ why she could speak English so well, she just smiled and said nothing.

A．asking

B．to be asked

C．was asked

D．asked

转录时编码链的序列是5′－TGACGA－3′，其转录产物的结构应该是（）

A.5′－TGACGA－3′

B.5′－ACTGCT－3′

C.5′－UGACGA－3′

D.5′－ACUGCU－3′

E.以上都不是