PN结具有（）单向导电性特性，即（）导通，（）截止。 A.选择，低压，高压 B.选择

数值孔径（numerical aperture）

监督检查不正当竞争行为的国家机关工作人员徇私舞弊，对明知有违反《反不正当竞争法》的规定构成犯罪的经营者故意包庇不使他受追诉的，依法追究( )。

A．民事责任
B．经济责任
C．刑事责任
D．行政责任

第四部分：写作（共三节）

短文改错（共10小题；每小题1分，满分10分）

Helen is one of my best friends. She had taught                     76. _________

us English when I attended training class two                               77. _________

years before. Helen always made good preparations                      78. _________

for the lesson, and she tried her best to make                                79. _________

her classes lively. I used to being poor in English,                         80. _________

especially in written English. But now I'm able                          81. _________

to write English letters and reports correct.                                   82. _________

I still remember how she helped me for my                               83. _________

English patiently. Teachers' Day's come. I'm going to                      84. _________

send to her a card and give her best wishes.                              85. _________

在施工图设计阶段，编制施工图预算时采用的是( )。

A．预算定额

B．概算定额

C．概算指标

D．企业定额

螺纹标记M20-6H表示（）。

A.普通细牙螺纹

B.普通粗牙螺纹

C.左旋

D.右旋

E.旋合长度长度为S

F.旋合长度为N