Work hard, and you’ll get good ________.

The underline part (划线部分) of “keys” is pronounced as（发音为）________.

一 The woman biologist stayed in Africa studying wildlife for 13 years before she returned to her country. — Oh, dear! She _____a lot of difficulties.[ ]

AIDS is said _______the biggest health challenge to both men and women in that area in the past three years.

The famous reporter, who is said to have gone back to America last year, _____in China for almost twenty years