Question

1 While they (walk) in the park, I (work) in the garden 2 My class mates (wait) for me when I (arrive) giúp tôi với

Answer 1

1. While they were walking in the park, I was working in the garden.    
2. My classmates were waiting for me when I arrived.

 

Answer 2

1 While they (walk) were walking in the park, I (work) was working in the garden

2 My class mates (wait) were waiting for me when I (arrive) arrived