The last decade of the 21st century ________ the rapid, steady development of China in various fields

Can you tell me what’s your aim inlife, Li Ping— I am aiming ____ a famous physicist

.I tried every means to reach my goal but failed. So sad ______ that I almost lost heart.

_____ your classmates and you will make more good friends.

After that terrible disaster, the officer had no choice but to _________ calm to deal with different problems.