According to the latest research, getting enough sleep is _____to maintaining good health and reducing stress.
#17753
A
practical
B
contradictory
C
essential
D
alternative
推荐题目
---Did you listen to the lecture? ---Yes, I have never heard a ___________ one. 
#18526
A
more exciting
B
more excited
C
most exciting
D
most excited
Grandpa is old, but he is still very ____.
#20612
A
living
B
alive
C
strong
D
younger