車の中に男の子が何人いますか。
A．なにひと
B．なんじん
C．なにじん
D．なんにん
参考答案：D
—Are these doctors and nurses tired, Mr. Smith?
—Yes. ________. They have been operating on the patient for at least 10 hours.
A．They’re exhausted!
B．You must be joking!
C．I’m not surprised!
D．They are really tired of it!
液压控制阀是液压系统中控制油液（）、（）及流动方向的元件。
