38GrMoAiA氮化HRC64～72，要求强度和耐磨性极高，高疲劳极限、变

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问题单项选择题

38GrMoAiA氮化HRC64～72，要求强度和耐磨性极高，高疲劳极限、变形小的零件。如主轴、滑动轴承的()、套筒等。

A、轴瓦

B、瓦盒

C、轴套

D、主轴

答案

参考答案：D

阅读理解

( )8.We can buy the fresh fruits ________.

A. in Marsha s house B. in Wawa Village

C. in Country Life Market D. in Next Wave Music Store

( )9. Mr. Green is planning to have a half-year holiday in California, but he can’t leave his pet dog alone, he should call ________for help.

A. 543-002 B. 544-996 C. 543-616 D. 544-471

( )10. According to the four ads, which is true?

A. Wawa Village is open only at night.

B. Marsha’s House does not offer food,

C. Country Life Market is newly opened.

D. Next Wave Music Store sells presents.

多项选择题

阳性强化法也称为( )。

A．奖励法

B．正强化法

C．积极强化法

D．鼓励法