seem常用于由as if/though引導(dǎo)的從句中，如：
a) It seems as if it is going to rain.
b) It seems as though our plan’ll be perfect.
c) It seems as if he knew nothing about that.
d) It seems as if it was/were spring already.
[注]在這種句式中，如從句所敘述的情實(shí)現(xiàn)的可能性比較大，從句謂語(yǔ)用陳述語(yǔ)氣
，如a,b兩例；若實(shí)現(xiàn)的可能性較小，或根本不可能實(shí)現(xiàn)，從句的謂語(yǔ)則用虛擬語(yǔ)氣，如c,d 兩例。