When ______ comes to research into heart disease and its effects on the body, we do not have adequate substitutes for the use of animals.
#93492
A
that
B
it
C
this
D
what
推荐题目
In fact___ is a hard job for the police to keep order in an important football match.
#92998
A
this
B
that
C
there
D
it
Let’s keep to the point, or we any decisions.
#94956
A
will never reach
B
have never reached
C
never reach
D
never reached
It is the first time that I _______ this kind of moon cake.
#92191
A
enjoyed
B
enjoy
C
have enjoyed
D
Enjoying
Tom was about to close the window ________ his attention was caught by a bird.
#92832
A
when
B
if
C
and
D
till