卷簧式机械示功器一般不适用于中、高速柴油机使用的原因在于（）_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题单项选择题

卷簧式机械示功器一般不适用于中、高速柴油机使用的原因在于（）。

A.示功器小活塞较大

B.示功器弹簧刚度太大

C.示功器自振频率较低

D.中、高速柴油机为四冲程

答案

参考答案：C

单项选择题

男，22岁，受凉后发热、咳嗽、胸痛1周，经抗感染治疗后胸痛消失，但出现胸闷、憋气、低热、乏力。查体：右中下肺叩诊浊音，呼吸音消失；血常规，WBC 11.2×10⁹/L，N 0.78。

X线胸片示右肺大片密度增高阴影，还需做下列哪项检查有助于诊断

A．B超

B．CT

C．ECG

D．胸穿抽液送检

E．ESR

补全对话，情景问答

给下列的问句选择对应的答语。

( ) 1. What's this?
( ) 2. What colour is it?
( ) 3. Where is your sister?
( ) 4. What's he doing?
( ) 5. How do you feel?
( ) 6. How many pencils do you have?
( ) 7. What's the matter?
( ) 8. How old are you?
( ) 9. How are you?
( ) 10. What's her name?

A. My knee hurts.
B. I have five pencils.
C. Her name is Kitty.
D. It's a birthday cake.
E. Fine, thanks.
F. It's green.
G. I'm ten.
H. She is under the tree.
I. I feel cold.
J. He is jumping.