it was so quiet in the classroom that a needle—-————to drop onto the floorAcould hear B was to be heard C could have been heard Dmust be heard古怪 c
问题描述：
it was so quiet in the classroom that a needle—-————to drop onto the floor
Acould hear B was to be heard C could have been heard Dmust be heard
古怪 c
答
B was to be heard
be heard to drop 应该没有问题吧?
hear sth/sb.do 的被动语态.
could be heard to drop 也是对的.
但没有,
be to do 是表示"注定,能够"的意思
与be heard to drop结合就是B了
was to be heard to drop .
太静,针掉地下都没听到.
C 是用的虚拟,本能听到却没听到,意思错了,
D 一定,意思不好,说的是能不能的问题,或许真有人就没听到.