Space exploration began in the 1960s, and since then about five hundred people into space.
_____ we have finished the course, we shall start doing more revision work.
I don’t like the way ________ Mr. Wang treats his children.
I meant to help him . ______, he didn’t accept my offer.
Several months later, he found his deskmate very difficult _______.
In order to make up for the lost time, they are working ______.