Last Saturday I C ___ for a bicycle ride with my friends. When I D ___ a bike, I saw a squirrel in the park.

The first blank (C) describes a past action. 'Went' is the simple past tense of 'go'. The second blank (D) describes an ongoing action in the past when another event occurred. 'Was riding' fits this context.

1. Choose 'went' for C.

2. Choose 'was riding' for D.