Here are the complete sentences based on the given cues:

1. John wanted to join the Science Club, so he completed the registration form.
2. Maria is not into building models as she does not have skillful hands.
3. Turn off your mobile phone; otherwise, you will not get into the test room.
4. His salary is higher, so he lived more comfortably than most people here.
5. If you study diligently, you will gain better scores on your exams.