润滑油温升高的原因不包括()。
A、油质不纯
B、油管或油路堵塞
C、破碎机研套
D、冷却器堵
参考答案:A
—What can you see in the picture?
—I can see a farm. And there ______ a lot of animals on it. [ ]
A. is
B. are
C. will be
D. be
接地线连接方法有哪几种?