August (八月) is the _____ month of a year. [ ]
A. ninth
B. eightth
C. nineth
D. eighth
答案:D
液体能均匀地黏附在固体表面的特性是()
A.假焊
B.流焊
C.润湿性
D.激光焊
E.压力焊
镁矽卡岩: