At sixty, Maugham decided to withdraw from the theater and wrote The Summer Up, in which he tried to review what he _______ from his life and literature.

Camels have three eyelids to ________ themselves from the blowing sand.

A huge _____ of quilts was needed in Qinghai province since it was freezing at night.

It’s widely accepted that young babies like to do things because certain acts lead to ________.

Liu Xiang’s talent for running and his ability to learn from his experiences________greatly to his many successes in sports.