1 l want to start my own business after l graduate from univ

1 l want to start my own business after l graduate from university (保持原句意思)
l’d _______ to start my own business after _______ from university
2Only you can help me in this task(保持原句意思)You_______can help me in this task
3The children must be back by 4o'clock (保持原句意思)The children ______ _______ be back by 4o'clock