Here are the completed sentences using the conditional type 1:

1. If you check your writing carefully, you won’t make mistakes.
2. If we leave right now, we will get there in time.
3. If Dave rides his bike on the pavement, he can be fined.
4. If Katie eats enough fruits and veggies, she won’t become deficient in vitamins and minerals.
5. If you don’t spend too much time in front of a screen, you will have time to study.
6. If you don’t fix your computer, you won’t be able to attend your online class.
7. If he practices speaking English frequently, he can improve his speaking skills.
8. If you study hard, you will pass the entrance exam.