乳尖牙的近中和远中出现间隙称为()
A.可用间隙
B.必须间隙
C.替牙间隙
D.灵长间隙
E.生长间隙
参考答案:D
(2013·辽宁五校第一联合体高三考试)—Who is the girl over there?
—Isn't that the secretary you want ________ the article?
A.to have type
B.her to type
C.to have typed
D.her type
如图所示的电路中,当开关S闭合,甲、乙两表是电压表时,两表示数之比U甲:U乙=3:2,当开关S断开,甲、乙两表是电流表时,两表的示数之比I甲:I乙为______.