西班牙梅罗卡20毫米高射炮被称为身管数最多的高射炮,问它有几根身管()
A.4
B.10
C.12
D.20
参考答案:C
在探究弹簧长度与力的关系时,选取甲、乙、丙、丁完全相同的四根弹簧,将甲、乙弹簧左端固定在墙上,用大小为F的力拉甲的右端,用大小为F的力压乙的右端,在丙弹簧左右两端施加大小为F的拉力,在丁弹簧左右两端施加大小为F的压力,四根弹簧都水平静止,如图所示,此时四根弹簧的长度分别是L甲、L乙、L丙、L丁,则( )
A.L甲=L乙=L丙=L丁
B.L乙=L丁<L甲=L丙
C.L甲=L乙<L丙=L丁
D.L丁<L乙<L甲<L丙
—Hi, do you think his uncle __________ this evening?
—I think he __________if it doesn’t rain.
A.will come; comes
B.will come; will come
C.comes; comes
D.comes; will come