At the top of the high mountains, there is very _____ oxygen in the air.
#40209
A
a little
B
little
C
a few
D
few
推荐题目
He is __________ than any other student in his class.
#37127
A
tall
B
taller 
C
tallest 
D
higher
Help ________ to some beef, Lucy and Lily. It’s very delicious.
#40695
A
yourself
B
yourselves
C
herself
D
themselves