在空气中易潮解,并吸收空气中的二氧化碳,而后在干燥的空气中又会风化的固体是()
A.氯化钙
B.生石灰
C.烧碱
D.氯化镁
E.硫酸钙
参考答案:B
Sam can sing English songs _________, but I can’t. [ ]
A. a lot
B. very good
C. very well
D. very much
18.5x-9.9x=1.72.