悬臂皮带运行时忽偏忽正的原因是什么?
参考答案:
(1)给煤不均匀。
(2)滚筒、托辊因固定不平有松动现象。
Can you ______ the difference ______ the two phrases?
A.tell, between
B.speak, from
C.say, of
D.talk, between
凝胶的含溶剂率越大,溶质透过性也越大