With out using and,but and so
1)It may rain we will remain at home
2He is rich i was in difficulty he did not help me
3)He came you had left before that
4)He saw me come he ran away

Dear Student,
Given below is the probable answer to your question as you have not provided the punctuations for the questions.

1. We will remain at home as it may rain.
2. Though he is rich, he did not help me when I was in difficulty.
3. He came though you had left before that.
4. He ran away because he saw you come.

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