—Your hamburger is the best I’ve ever tasted, Ms. Black!

—Thanks, Harry. _____.

A．That’s easy to make

B．I learned it from my parents

C．Please don’t say so

D．I’m glad you enjoyed it

筒冠内冠试戴时就位后龈缘发白，最有可能的原因是（）

A.有悬突

B.内冠颈缘过长

C.内冠不密合

D.内冠变形

E.以上都不是