Ответ:

If you eat fast-food, you will become fat.

If you have time later, will you help me with dinner?

If you don't learn the key vocabulary, you will won't pass the test.

The teacher will give her a low mark, if Kate forgets her homework.

If he has a temperature, he will see the doctor.

Объяснение:

If I/we/you/they + do,

If he/she/it + does,

(then)

I/we/you/he/she/it/they will/won't do (positive/negative)

Will I/we/you/he/she/it/they do (question form)

Will not = won't

Do not = don't

Does not = doesn't