I ___ Japanese since 1977.
A.have been learning
B.learn
C.have learn
D.is learning
答案:A
A.1m3铜中含有的铜原子数目是ρN/M
B.1Kg铜含有铜原子数目是ρN
C.一个铜原子的质量为M/ρN
D.1个铜原子占有的体积是MN/ρ
脾其华在()
A.口
B.唇
C.发
D.面
E.爪