金属油罐使用一定时间后,要进行腐蚀情况检查.罐底和灌顶内部在清罐时要进行防锈、防腐.对有保温层的油缸,要定期进行外层铁皮的刷漆防腐,使其无破损和脱落.
参考答案:对
It was very __________ of you to let us know you were going to be late.
A.considering
B.considered
C.considerable
D.considerate
等价划分一般为那两种情况,它们分别是什么简述两者概念?