用所给词的适当形式填空
Tom spent most of his time searching for information on the Internet each day, which made his parents worried. In his father’s opinion, 16 (sit) in front of a computer did great harm to his son's health. However, he found that it was no use 17 (advise) Tom to spend less time on the Internet, for he wouldn’t listen. Tom told his parents that that was what his job required. His mother wanted him to change his job, but Tom said that he was fond of it and 18 (stay) up late had become his habit.
In my opinion, it is not wise to spend too much time on the Internet. 19 (have) a rest regularly will be of great help while working at the computer. In addition, 20 (set) aside some time to relax is also very important.