— You seem to know much about the city.

— That’s true. I_____ it five times in the past two months.[ ]

A. visited                    

B. am visiting

C. have visited          

D. will visit

对关节的描述，正确的是()

A.关节面表面有一层纤维软骨覆盖 

B.所有关节均有关节盘 

C.关节囊的纤维膜与滑膜之间腔隙称为关节腔 

D.关节腔内为负压，并有少量滑液 

E.所有关节均有囊内韧带