江苏省徐州市2014
高考英语单项选择练习（9）及答案单项选择 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
