A: What do you think will happen if we eat too much fast food?
B: If we eat too much fast food, we'll nutrition deficiency.
A: What do you think will happen if we spend all day at the beach?
B: If we spend all day at the beach, we might get dark-skinned more than ever before.
A: What do you think will happen if we use cell phones in class?
B: If we use cell phones in class, we won't understand the lesson.
A: What do you think will happen if we never study English?
B: If we never study English, we won't listen, speak, read, and write English at all.
A: What do you think will happen if we don't get enough sleep?
B: If we don't get enough sleep, we'll feel fatigue.