1. I was lucky. I found the solution (in/by/on) accident.
2. We can't go by train. The train-drivers are (in/by/on) strike.
3. They've promised me more money, but I haven't got it (in/by/
on) writing
4. I was (under / by / out of the impression that you enjoyed work-
ing here.
5. You can contact me (at/on/by) the phone or (at/on/by) e-mail.
6. Sometimes in a shop they ask you: “How do you want to pay?"
You can answer: "(In / On/By) cash. (In / On/By) cheque. (In /
On/By) credit card."
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