Past Simple or Past Continuous?

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
1. It(snow) when I(come) to work this morning.
2. Lucy thinks she (drop) her purse while she (shop).
3. Your boss (try) to call you while (phone) in the other office.
4. Tom and Sue (meet) while they (be) on holiday.
5. Yesterday it was so hot that we (swim) in the river all day long.
6. David came to see me so I (take) him out to lunch.
7. When I (enter) the house my mother (read).