根据句意和汉语注释，写出单词的正确形式。
【小题1】When the doctor arrived, the victim had already stopped __________(呼吸).
【小题2】The dry weather in Southeast China has been the main _________(原因) of the forest fires in the area since last autumn.
【小题3】The students often make __________ (相似) mistakes.
【小题4】In this Italian restaurant, you will have the chance to try everything _________(不同) from that in a Chinese one.