问题

it is normal for parrots to talk, Einstein, a small bird, is unusual in that whenever she hears a new word or sound, she repeats it over and over until she masters it.

A:As
B:When
C:While　　/T
D:Since

正确答案是：

同类题型

Great changes have taken place in that school. It is no longer _____it was 20 years ago, ______it was so poorly equipped.

They are talking ________ my parents _______ my study.

When you do exercises, your heart works better. It is able to______ more blood while beating more slowly.

Help yourself to __________