当MUST解释为大概 表猜测时 后面的动词是不是不能再用原形拉e.g:She thought that her present must ____ in the box.

问题描述:

当MUST解释为大概 表猜测时 后面的动词是不是不能再用原形拉
e.g:She thought that her present must ____ in the box.

是只能加动词原形,因为MUST是情态动词