A. 正确 B. 错误
A. 政府投资 B. 社会集资 C. 企业融资 D. 个人
A. 菱形结构 B. 梯形结构 C. 正金字塔结构 D. 倒金字塔结构
A. prevent excessive cylinder liner wear B. reduce friction losses in the engine C. seal the space between the piston and the liner D. limit upward flow of lube oil into the combustion space
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