You’d better write down her phone number before you _______ it.

This is the best way ______ I have thought of ______the problem.

在文中横线处填入下列语句，衔接恰当的一项是（ ）如果有黑洞撞向地球，那么________。当然，你听到的不是声波，而是引力波，因为________。当黑洞靠近时，引力波会“挤压”内耳骨，产生类似照相机闪光灯充电时发出的咝咝声。尽管天文学家认为，________，但正常情况下，________，因为引力波在广袤的宇宙中经过长途跋涉，抵达地球时强度已大大减弱。①引力波每时每刻都在影响着我们 ②你会听到它悄然逼近的声音 ③引力波是听不到的 ④声波在真空中无法传播

______of the teachers in the school are from the famous colleges.

It is only with the help of scientific research _____ bring PM1 air pollution under control.