______ has an internal clock that regulates the beating of our hearts, and the ______ of our breathing. 
#13261
A
Mankind; step
B
Human; pace
C
Human being; step
D
Man; pace
推荐题目
Do you think that bridge ____ 2,000 meters long? It doesn’t seem ____ long. 
#10939
A
measures, that
B
is measured, so
C
is measured, such
D
measures, much
 Being afraid of making mistakes,the little boy ____answer his teacher’s question.
#12178
A
does dare
B
doesn’t dare to
C
daren’t
D
not dare to
They were very ________ when they heard the ________ news that he would come back in two days.
#11646
A
surprising; surprised
B
surprising; surprising
C
surprised; surprising
D
surprised; surprised