1. You can call this number whenever there is any difficult.
-> If there is any difficulty, you can call this number.
2. "How old is your little daughter now?" said the doctor.
-> The doctor asked me how old my little girl was then. 
3. The book is so good that I can't take my eyes off.
=> It is too good for me to take my eyes off.
4. The boy will receive some money to continue his study. His parents died in a traffic accident.
=> The boy whose parents died in a traffic accident will receive some money to continue his study.