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【多选题】
滚齿时，齿轮基节超差的原因是（）。
A.
齿坯安装偏心
B.
分度蜗轮误差大
C.
分度蜗杆松动
D.
升降丝杠松动
E.
工作台下压板间隙大
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参考答案：
参考解析：
刷刷题刷刷变学霸
举一反三
【单选题】Passage 3 Questions 11 to 15 are based on the following passage: Scientists in India have invented a new way to produce electricity. Their invention does not get its power from oil, coal or other fuel...
A.
Because bullocks have long been used by Indian people
B.
Because bullocks walk slowly and are easy to control.
C.
Because there are few non-working bullocks in India
D.
Because there is not enough oil in India.
【单选题】培养基的冷却方式有喷淋冷却式、真空冷却式、薄板换热器式几种方式，其中（）效率高，且利用冷培养基作冷却剂，既冷却了热培养基，又预热了冷培养基，节约用水和蒸汽。
A.
喷淋冷却式
B.
真空冷却式
C.
薄板换热器式
D.
A+B+C