. _____ can be enjoyed until you have a deep understanding of the low-carbon lifestyle.
—Did you return Fred’s call? —I didn’t need to ____ I’ll see him tomorrow.
Many children, ______ parents are away working in big cities,are taken good care of in the village.
____ parents say and do has a life-long effect on their children.
—She looks very happy. She ______ have passed the exam. —I guess so. It’s not difficult after all.
____ he had not hurt his leg, John would have won the race.