1. He worked hard to pass the examination.
2. Only Hindus are admitted.
3.His silence proves his guilt.
Kindly change the above sentences into complex.
Only the bold blue words are to be changed.
It was not clear from your question Any way please look at these:
1. He worked hard because he had to pass the examination.
2. This is a restricted institution of Hindus who are admitted.
3.He prefers to be silent which proves his guilt.