He stayed up too late every night,______ to catch up with his classmates.

Although his experiments were designed to support the ideas       the influence of environment upon plants, Mendel found that many characteristics were passed on from one generation to the next.

--- Jack Chou will give a concert at the City Stadium on Sunday evening. ---- Where did you ____ that?

The Internet gives people the chance to have the information they need ______ to them quickly and cheaply.

In the speech, the headmaster recommended the students not to ______ with dishonest people if they value sincerity and honesty.