Here are the sentences rewritten in the passive voice:

The roads are covered with the snow.

My dress is clean now. It has been washed.

I can’t give you these articles. They are being translated now.

These houses were built in 1500.

She showed me the picture that was painted by her husband.

Tennis was played by the children from four till five yesterday.

The letter will not be written tomorrow.

When will the next picture be finished?

It was very dark. Nothing could be seen.

The guests must be met at noon.