粘土砖能够抵抗()的侵蚀。
A、酸性炉渣
B、碱性渣蚀
C、FeO
D、FH
参考答案:A
劳动生产率水平的高低主要受哪些条件影响?
—Mum, could I play with my classmates for a while after I finish my homework?
— ________. But you must come back before supper.[ ]
A. Yes, you can
B. Yes, you could
C. No, you can't
D. No, you couldn't