present simple - past continious - past perfect.
1. It ___ when we ___ home.
A) was snowing, were leaving
B) snowed, left
C) was snowing, left
2. While my friend, I the birds.
A) had fished, was watching
B) fished, watched
C) was fishing, was watching.

It was snowing, when we left home.While my friend was fishing, I was watching the birds.

present simple - past continious - past perfect.

1. It ___ when we ___ home. C) was snowing, left

A) was snowing, were leaving

B) snowed, left

C) was snowing, left

2. While my friend, I the birds. C) was fishing, was watching.

A) had fished, was watching

B) fished, watched

C) was fishing, was watching.