填空题 (No wonder) that (man's) great dream has been someday to control the weather. The first step toward control is, of course, knowledge, and scientists have been (hard at work) for years trying to (keep track for) the weather. A. No wonder B. man’s C. hard at work D. keep track of
  • 1、
【正确答案】 1、D改为keep track of    
【答案解析】keep track of，固定结构，意为“保持联系，明了”。