it ------- be difficult to learn it.have you triedA shall B must C should D need
问题描述:
it ------- be difficult to learn it.have you tried
A shall B must C should D need
答
B must
学习它一定很难吧,你试过了吗?
答
it is difficult to learn it.have you tried?
学习这很难 你累了吗?
答
B
表猜测用must