1. Sustainable development is long-term ______which focuses on the environment and _____ natural resources.
A. plan; preserve B. plan; preserving C. planning; preserving D. planning ;preserve
2. A giant helium(氦) balloon is telling residents of Paris how good or bad the air quality is. When it’s good, the balloon ----measuring 22 meters wide and 32 meters high---shines green. _________, it’s red.
A. Though terrible B. Whenever good C. If worse D. When bad
3. Playing QQ’s “Happy Farm” by planting, watering, fertilizing, spraying, harvesting and selling of virtual vegetables, fruits and flowers, we can find out _____ all the excitement is about.
A. that B. if C. what D. when
