—Do I need to give a tip if I eat at a fast food restaurant in the United States?—Yes , it’s a common       to tip waiters in a restaurant.

The system has been designed to give students quick and easy________to the digital resources of the library.

I bought a dress for only 20 dollars in a sale; it was really a good ______.

We should make a careful study of his____.

This book gives a brief ________ of MoYan’s growth and details of his writing experiences.