The picnic was cancelled because it rained. => if...................................; 2.Susan felt sick because she ate four cream cakes => if.........................

1. The picnic was cancelled because it rained
==> if
2. Susan felt sick because she ate four cream cakes 
==> if
3. If the weather is fine, we'll go hiking this weekend
==> if
4. If you work hard, you will pass the exam
===> unless