根据句义和给出的汉语注释或首字母写出单词的正确形式。（每空一词）

1．Wang Ping is the______（第二）tallest student in Class One，Grade Nine．

2．Many teenagers like c     with their friends through QQ on the Internet．

3．It is very important for schools to keep students_______（安全的）because some of them were killed or injured．

4．He came into the room______（安静地）because the baby was sleeping．

5．Shanghai is one of the biggest c      in China．

1、1．second“

2．chatting

3．safe／secure

4．quietly／silently

5．cities