下面各式中,是方程的是 [ ]
A.x÷5
B.3x+4<2x+8
C.5x+2=7
答案:C
—Maria is wanted on the telephone. Where is she?
—She ______ the library. You can find her there. [ ]
A. has been to
B. has gone to
C. has left
D. has been in
简述先秦时期管仲财税改革及其影响?