用所给词的适当形式填空。

1. Most people speak English as a _____ (two) language.

2. Have you ever spoken to a _____ (nation) speaker?

3. I learn English by _____ (make) up conversations with my friends.

4. This kind of coffee tastes very _____ (well).

5. Her _____ (pronounce) is very good.

关于快速进展型牙周炎的发病特点，不正确的是（）。

A.发病年龄青春期35岁

B.病损累及大多数牙

C.菌斑的沉积量较少

D.部分有青少年牙周病史

E.严重及快速的骨破坏