系统降压、降温必须按要求的幅度（速率）并按（）的顺序进行。
A.先低压后高压
B.现高压后低压
C.先前面再后面
D.先后面再前面
参考答案：B
—Alas! I have left my key to the office in my car.
—Don't worry. I ________ it for you. Wait a minute.
A．get
B．am going to get
C．will get
D．am getting
草案
