京杭大运河上现存唯一的一座七孔石拱桥是（）。
A.广济桥
B.宦塘桥
C.长虹桥
D.拱宸桥
参考答案：A
After decades of construction and development, Tibet is _____ its best-ever time of progress and stability.[ ]
A. appreciating
B. enjoying
C. winning
D. seizing
跃进防守
