1\She is going to send a letter to her sister.
她准备给她的姐姐寄封信.
这句能不能写成:She is going to send her sister a letter.??
2\ He sent his secretary for a doctor.
这里为什么用for而不用请的单词:invite.这是为什么呢?
Her mother often sends her to the store for some groceries.
她母亲经常差遣她去商店买些杂货.
for这里为什么不用buy,buy是买的意思为什么用for?
请大家告诉我一下,谢谢!