I don’t think it is __________taking the trouble to explain the question to him.

Two men, starting at the same point, walk in opposite directions for 4 meters, turn left and walk another 3 meters. What is the distance between them

To everyone’s surprise, the difficult question was answered by a five-year-old boy in the end [ ]

－_______ is your mother －She is fine!

In the front of the hall _______ a group of pupils, who were listening to the lecture attentively