将等质量的两份锌粉a、b分别加入过量的稀硫酸中,同时向a中加入少量硫酸铜溶液,下列各图产生H2的体积V(L)与时间t(min)的关系中正确的是 [ ]
A.
B.
C.
D.
答案:A
You are old enough to _____ your own living. [ ]
A. win
B. gain
C. take
D. earn