When it ______ research into heart disease and its effects on the body, we do not have adequate substitutes for the use of animals.
#71865
A
refers to
B
related to
C
comes to
D
talks to
推荐题目
The cinema was crowded with many people, ____ many children ____ on their parents’ laps. 
#72855
A
including; seated
B
including; seating
C
include; sat
D
included; sitting