—_______ is your new bike, Xiaohua?
—It is 580 yuan.
A:How much
B:How many
C:How old
用化学符号表示:
——Whom are you going to the zoo with?
——I'm not sure __________.
如图所示,放在M、N两水平桌面上的P、Q两物体,分别在FP=5N、FQ=3N的水平拉力作用下做匀速直线运动,可以确定()