从以下4个小题中，选出与各句画线部分意思相同或相近、并能替换画线部分的选项。（共4小题，每小题1分；计4分）

A. did nothing   B. were important    C. as long as     D. is less hard-working than

The excellent performers played a good role in this interesting show.
In the past summer vacation, I didn’t do anything special.
Mike doesn’t study as hard as his young sister.
You will get better grades if you choose the right way of learning.