Chang’e2 did many experiments, ______ I think are of much help for knowing space.
#76050
A
which
B
what
C
when
D
where
推荐题目
Wind power is an ancient source of energy we may return in the near future.
#77113
A
on which
B
by which
C
to which
D
from which
Zheng He had over 300 ships, _______ some were over 150 meters long and could carry up to 1,000 people.
#76961
A
that
B
which
C
of which
D
on which
Between the lectures is a 20 minutes’break，__________the students can get relaxed.
#75419
A
that
B
which
C
where
D
when