Nowadays，it is common to see people staring at their mobile phones instead of reading a real book，＿＿＿＿＿＿many experts are worried．
#75642
A
when
B
for which
C
where
D
about which
推荐题目
It’s helpful to put students in a situation _______ they can learn how to cooperate with each other.
#75207
A
that
B
when
C
which
D
where