—We some shopping in the supermarket.
A:do
B:did
C:are doing
D:were doing
选择恰当的关联词填空。
( )人人能学法、懂法,社会风气( )会很快好转。
— Can I take photos here?
— You'd better not. Look at the sign “______” .
如图所示,甲图是动圈式话筒,乙图是动圈式扬声器的结构图,其中