He found it impossible to please his boss; ____, he quit the well-paid job

Danny, pick the flowers in the park.

It was not until the supreme lending crisis (次贷危机)had caused great damage to the American financial system ______ Americans realized the severity (严重性) of the situation. [ ]

It’s raining________and people can________go out.

Not until ________ in the college entrance exam ________ that he had wasted much time using his mobile phone to surf the Internet and play games.