When ____ comes to research into heart d
题型:选择题
问题:
When ____ comes to research into heart disease and the effects on the body, we do not have
adequate substitutes for the use of animals.[ ]
A. that
B. it
C. what
D. this
When ____ comes to research into heart disease and the effects on the body, we do not have
adequate substitutes for the use of animals.[ ]
A. that
B. it
C. what
D. this