根据句意及首字母提示， 把句子所缺单词补充完整。
（1）The months of winter usually are N ________,D _________ and J _____.
（2）Shanghai is in the e _______ of China.
（3）Teachers' Day is on the t _______ of S _______.
（4）The ball is 200 yuan. It is d _______.
（5）This plane f ______ to Guangzhou every day.
（6）Beijing is a b ______ city.
（7）The box is h _____. I can't carry it.