A NASA experimental jet , the X-43A,flew at a world –record speed ---11,260 kilometres an hour on November 17.This speed is __ as that of sound.
He wouldn’t leave the TV set, ______ he was going to have an important exam the next day.
As soon as she saw her boyfriend, she ________ crying.
—May I ask a question after class,Sir? —, but not during my lunch break.
The scientists have made _______ possible for us to communicate with each other more easily.
You’d better your score and see if you have passed the exam.