用括号中词的适当形式添单词;
小题1:It’s a good habit to brush ___________(tooth)three times a day.
小题2:If there are more trees on the earth, there will be ________(little) pollution.
小题3:I hope to finish __________(write) my first book by the end of the year.
小题4:Thanks for _______(give) me so much help with my English.
小题5:More natural reserves(保护区) will be _________(build) in our country in the next few years.