若等差数列{an}的前5项之和S5=25，且a2=3，则a7=[ ]
A.12
B.13
C.14
D.15
答案：B
The old bridge,________300 years ago,was washed away by a heavy flood last summer.[ ]
A. building
B. to be built
C. to be building
D. built
位于肱二头肌腱内侧的组织是（）
A.尺神经
B.肱血管
C.腋神经
D.旋前圆肌
E.桡神经
