活塞上压力维持恒定的汽缸内有0.2kg压力为400 kPa的干饱和蒸汽。使其冷却到体积为原有体积的一半，试确定过程

A. They occur at regular intervals.
B. They can withstand great heat.
C. They travel through the Earths interior.
D. They can record the Earths internal temperature.

A. How deep they are.
B. Where earthquakes form.
C. How hot they are.
D. What purpose they serve.

A. Wash fewer clothes at a time.
B. Use a different washing machine.
C. Try to repair the washing machine first,
D. Wash his clothes by hand.

A. Hell give the woman a few prescriptions right away.
B. Hell be away from the office for one or two days.
C. The woman doesnt need anything for her cough.
D. The woman should continue taking the medicine.