Choose the best words to complete the sentences.

Choose the correct option.

Don't worry. I'll reach home [plain|white|quick|safe] and sound.

This question isn't very difficult. It seems to me that the answer is as **** [plain|white|quick|safe] as a day.

I'll be on time, I am as [plain|white|quick|safe] as a flash.

When he heard of her accident, he turned as [plain|white|quick|safe] as a sheet.