香香和可可背对背站立,香香向北走130米,可可向南走180米,两人相距多少米?
130+180=310(米),
答:两人相距310米,
Mr. King, would you mind _____ the books there? [ ]
A. put
B. putting
C. to put
下列阳离子中,能与氨形成络离子的是()
A.Ca2+
B.Fe2+
C.Sc+
D.K2+
E.Cu3+