据下面各题的意思，写出括号里所给的词汇的正确形式。

1. Mr. Smith lives on the _____ (six) floor.

2. Their teachers are as friendly to students as _____ (we).

3. Look! Ms. Gao and her children are _____ (ride) bicycles on the Green Way.

4. Maria's parents will go to the airport by taxi because it is raining _____ (heavy).

5. If at first you don't _____ (success), try, try again.