When _____ to hand in his homework, Philip told his teacher that he had left it home.
It’s helpful to put children in a situation _____ they can see themselves differently.
— I’ve read another book this week. — Well, maybe _____ is not how much you read but what you read that counts.
—How about your journey to Mount Tai ? —Everything was wonderful except that our car ____twice on the way.
The traffic lights ______ green and I pulled away.
Someone who lacks perseverance is unlikely to _______ a good researcher.