根据句意，写出括号内所给单词的适当形式。

【1】—I've never seen such an_________（tidy）room.

—Sorry, Mum, I'll clean it up right now.

【2】If you are will to work harder ,people will become even ________(wealth)?

【3】The teacher doubled the ____________(true) of his excuse.

【4】It was raining _______ (heavy)at that time and we had to wait for some time.