单项选择题
Cracks in the cylinders and cylinder covers may （） unequal heating.
A.result from B.result in C.give out D.given from
单项选择题 Cracks in cylinder and cylinder covers may （） from unequal heating.
单项选择题 Cooling of engine is achieved by circulation a cooling liquid around internal passages within the （）.
单项选择题 Cooling enables the engine metals （） their mechanical properties.
