背离《国际海上避碰规则》的条件是:()
Ⅰ、危险确实存在Ⅱ、危险必须是紧迫的Ⅲ、背离是合理的
A.Ⅰ、Ⅱ
B.Ⅰ、Ⅱ、Ⅲ
C.Ⅱ、Ⅲ
D.Ⅰ、Ⅲ
参考答案:B
Jack is ready ______ you ______ English. [ ]
A. help, learn
B. to help, learning
C. help, learning
D. to help, learn
凝结泵轴承温度高的原因有哪些?