My friend, Tony likes playing computer games and _____ on Internet. [ ]

A. chating

B. to chat

C. chatting

D. chats

根据句意和汉语注释，写出单词的正确形式。

小题1:I wonder how many ______ (手术) ORBIS doctors perform during their visit to a poor country.

小题2: You won’t see this kind of insect _______ (遍及) the whole winter.

小题3:September is the _________(九) month of the year.

小题4: Children’s behavior is often _______ (影响) by what their parents do.