Question

英语语法题

英语语法题When _____ a picture taken,you should try to smile.

have / having / to have / had
可以给个详细解释吗

Answer 1

having
考查非谓语动词作状语的用法。此用法【非谓语的逻辑主语需与主句主语一致】。故分词的逻辑主语该是you.
当你拍照时，你该微笑。
现在分词和过去分词作时间或条件状语时，可在其前加when/while/if/unless/even if等。
如：
(While) reading in bed , he heard the strange noise.
If invited ,I'll attend the party.