I spent the whole day repairing the motorbike. The work was ____ simple.

He accidentally _____ he had quarreled with his wife and that he hadn’t been home for a couple of weeks.

Will you _____ the clock? It’s slow.

The government has decided to give preference to those environmently-friendly business and companies in all aspects in _______ of sustainable development.

The _______ income of the common people has been greatly increased in the past thirty years ______ the reform and opening-up policy in China.