by himself 和himself一样吗1."如果他能独立做完...":if he can finish writing...by himself,可不可以不用by?2.body language 还是body languages?

问题描述:

by himself 和himself一样吗
1."如果他能独立做完...":if he can finish writing...by himself,可不可以不用by?
2.body language 还是body languages?

可以无s

强调独立完成。
用单数形式。

1.可以
2.body language