一 Why are you so 1ate? 一 I got stuck in the traffic jam, or I _____earlier. [ ]

To our surprise the stranger _____ to be an old friend of my mother’s.

The question _______ we can get enough coal for the winter has not been cleared up yet

Did youunderstand what the teacher said —Yes! She explained the text in detail to make herlessons __________.

Which module is the most difficult in this book— I think _____ module.