You have to wear a helmet and a life jacket for protection, just ___ you fall into the water.

I’m sorry you ______ so long, but it’ ll still be some time before Jim gets back

Usually a child’s behavior is a ________of his family environment.

She didn’t pass the exams becauseshe________ her lessons well.

My phone ________ have been stolen while I was taking a bus. I can’t find it anywhere.