20世纪50年代以前曾经广泛应用的横道图的发明者是()
A.甘特
B.韦伯
C.蒙特卡罗
D.泰勒
参考答案:A
V带传动具有传动平稳、振动小、摩擦力较大、不易()等优点。
—Hi, guys. Where are you heading now?
—Home. We _______ all our money, so we have to walk home now.[ ]
A. spend
B. spent
C. have spent
D. are spending