当你按下按钮时，机器会发出高音调的声音。

The machine ___emits a high-pitched sound when you press the button.

所有车辆和工厂排放烟雾，这些烟雾会导致严重疾病，如癌症。

All the vehicles and factories ___emit fumes, which cause grave diseases such as cancer.

科学家测量恒星发射的红外辐射以确定其温度。

Scientists measure the infrared radiation that stars ___emit to determine their temperature.