— Hi, Wang Xin! What attracts you so much in today's Jinling Evening News?

— I'm quite impressed by ________ latest news that ________ senior citizens can enjoy free fares. [ ]

A. a; the

B. /; the

C. the; /

D. the; the

窝沟封闭成功的关键是（）

A.酸蚀时间长

B.酸蚀面积大

C.光固化时间适宜

D.涂布封闭剂气泡

E.酸蚀后不被唾液污染