问题
选择题
The teacher won’t begin the class ______ all the students ______.
A．until ; stop to talk
B．until; stop talking
C．if; stop to talk
D．if ; stop talking
答案
答案：B
此题考查了两个知识点“not...until”意为“直到...才”和“stop to do sth”与“stop doing sth”的区别。