沥青质是很重的（）组成的粘稠基烃类，它在常温下细的，粉状的，（）的固体。
参考答案：稠环芳烃等、棕黑色
— What would you like _______ your afternoon tea？
— Just a cup of coffee _______ some sugar and milk.
A．of; with
B．of; without
C．for; with
D．for; without
如图所示，倾角θ=30°的斜面上，用弹簧系住一重为20N的物块，物块保持静止，已知物块与斜面间的最大静摩擦力为Fm=12N，那么该弹簧的弹力可能是
A．2N
B．10N
C．20N
D．24N
