用所给单词的适当形式填空。
(1)December is the ____ (twelve) month of a year.
(2)As we all know, the silk dress feels____ (soft).
(3)She said to the twins, "Help ____ (you) to some fruit.”
(4)You should do your homework as ____ (careful) as your sister.
(5)The foreign teacher gave us some____(advice) on how to learn English.
(6)____ (teach) high school students in a poor mountain village may not sound like fun to you.