A:炼铜工业、钢铁工业、精密仪表
B:航天工业、电子工业、高档服装
C:印刷厂、家具制造、水产品加工
D:制伞、炼铜、集成电路
如图是测量硬币直径的图示.则该硬币的直径是____ mm.
I can't read the book by myself because there are ______________ new words in it.
—No. Neither of us ______.
(2)图甲的实验中,B组的作用是_____________ _________。