伞边缘半径为，且高出地面为，若使雨伞以角速度旋转，求雨滴自伞边缘甩出后落于地面形成的大圆圈半径。

用单词的适当形式填空。

1.  He ________ (like) junk food, so he thinks French fries are ________ (good) than rice.

2.  He failed the exam yesterday, but he________ (try) his best to study________ (well).

3.  My healthy lifestyle________ (help) me________ (get) good ________ (grade).

4.  Jane's lifestyle is the same as ________ (Tom).

5.  Young children should try________ (speak) more English.

6.  This book is________ (difference)  from that one.

7.  The two pictures are________ (different). There are six________ (different) in

    them.

8.  Here________ (be)a letter for you.

9.  We had________ (little) snow this year than usual (往年).

10.  He kept________ (run) after, trying to catch her.