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
This monument was built in honor of the scientist who was believed ______ the first telephone.
A.to invent
B.to have been invented
C.to have invented
D.having been invented
2/3,1/2,2/5,1/3,2/7,()。
A.1/6
B.2/11
C.1/4
D.2/9