1.if/ they/ not come/ her/ we / not be/ happy.
If they don't come with her, we won't be happy.

2.we/ go/ picnic/ if/we/ have/ much/time

We will go for a picnic if we have much time.

3.everyone / can/ eat/ inside/ if/ it / rain

Everyone can eat inside if it rain.

4.unless/i/ be/ busy/ i / go/ sightseeing/ you

Unless i am busy, I will go sightseeing with you.

6.she/ take/ photos/ if/ she/ have / camera

She will take photos if she has a camera.

5.if/ children/ go/ near/ nick's dog/ it/ bite/ them

If the children go near Nick's dog, it will bite them.

7.i/ write/ a letter/ you/ if / i/ know/ address

I will write a letter for you if i know your adress.

8.if/ he/be/ good/ all/ subiects/ parents/ be/ satisfied

If he is good at all subjects ,his parents will be very satisfied.

=>
1. If they don't come here, we won't be happy.
2. We will go for a picnic if we have much free time.
3. Everyone can eat inside if it rains.
4. Unless I am busy, I will go sightseeing with you.
5. If the children go near Nick's dog, it will bite them.

6. She will take photos if she has a camera.
7. I will write a letter to you if I know your address.
8. If he is good at all subjects, his parents will be satisfied.