-------- your composition carefully,some spelling mistakes c

这句意思很明显
如果你检查的仔细点,一些拼写错误是可以被避免的.
第一个是表示已经仔细检查过了,第二个是错的,第四个是表示一个目的,而不原因
再问： 那A的这种用法适合用在哪里？？ 还有having done 和doing如果在句首用哪个
再答： 给你举个例子

Having checked his composition careflully, Jim hand it over to the teacher and leave.

Jim went to the playground, playing football.

伴随状语不被主句时态影响