Some students were late for class because they hadbeen _________ by the heavy storm.

She was told to wear flat shoes _____her back problem[ ]

she said this, she regretted it

So far we have done a lot to build a low-carbon economy, yet it is still _________ idealWe have to work even harder

At night, plants _________carbon dioxide and at the same time _________oxygen. So, we may put some in our bedrooms to purify the air.