you are smoking a lot.

问题描述:

you are smoking a lot.
only at home no one ( )me but you.
A,is seeing B,had senn C,sees D,saw

选a,根据时态呼应原则,问题的语境是正在进行的时态,强调正在发生,所以选ab是过去完成时强调对过去的影响,于现在无关,d同理,c表示经常发生,不符