Three minutes earlier ____ we could have caught theearly train to Philadelphia

The program “Master’s Lectures” of CCTV is both interesting and instructive. No wonder it _______ a large audience.

______ do you spell your family name—C-L-A-R-K, Clark.

In the last ten years, they _______ three great scientific experiments.

What took you so long— I got lost. I have no ________ of direction.