问题
选择题
You stepped into the lab with your shoes on? You’re _______ to take them off before you enter it.
A．invited
B．supposed
C．forbidden
D．permitted
答案
答案：B
考查动词。be supposed to do应当做某事。根据句意你进实验室之前应当把鞋脱了，选B。
搜题请搜索小程序“爱下问搜题”
