根据句意，在答题卷标有题号的横线上，写出括号内所给单词的适当形式。
Our __________ (three) lesson begins at 9:55 a.m.
I usually go to school on __________ (feet) because my home is close to the school.
— Do you like any special holidays?
— Yes. We have lots of fun on __________ (child) Day.
You should try your __________ (good) to learn English well, for it is very useful.
He likes playing basketball and he is one of the greatest __________ (play) in his school.