In the following sentences put one of the verbs in brackets into the Past Continuous and the other verb into the Simple

While Mary was washing up, she broke a cup. 

While we were waiting for the train, it started to rain.

Jim studied to be a doctor, when he met Sally.

I first met Mr Rodrigues when I was going round Mexico on a marketing trip.

When she was giving her presentation, someone at the back of the room interrupted to ask a question.

While my PA was finalizing arrangements for my trip to Brazil, the clients rang up to cancel the visit.

The auditors noticed a large unauthorized withdrawal when they were looking through the account. The worker who died was cleaning the chemical tank when the accident happened. One of the removal men dropped my computer when he was taking it into my office.

A headhunter approached her when she was working for ICL.