单项选择题 We can learn from the beginning of the text that doctors in Philadelphia()
单项选择题 By mentioning "double-dipping" (Paragraph 4), the author is talking about()
问答题 Directions: Study the following picture carefully and write an essay entitled "Noise Pollution. " In the essay you should (1) show your understanding about the issue, (2) state your opinions and use facts to support your statement.