问题
选择题
______ the teacher has given permission, ______allowed to use the equipment in the lab.
A．Only if, are the students
B．If only, the students are
C．If only, are the students
D．Only if the students are
答案
A
题目分析：句意：只要老师答应，学生被允许使用实验室的设备。这里是only修饰if的从句放在句首时，句子的主句用部分倒装，故选A。