第23题: [单项选择]船用大型低速机的气缸注油器在结构原理上的特点一般为()。 A. 注油量可调,注油正时可调 B. 注油量可调,注油正时控制困难 C. 注油量不可调,注油正时可调 D. 注油量、注油正时均不可调 参考答案:B
第24题: [单项选择]If it ______ for the snow, we ______ the mountain yesterday. A. were not; could have climbed B. were not; could climb C. had not been; could have climbed D. had not been; could climb 参考答案:C