Ancient man attempted to change the weather by using
　　magic．While experience taught him this was impossible, __1__
　　he tried to forecast weather conditions．Even earlier in __2__
　　1000 B．C．there were weather seers in Babylon----and
　　priests clever enough to denounce as frauds those predicted __3__
　　the weather a year in the advance．Some forecasters used __4__
　　methods that seemed to take no connection with the actual __5__
　　factors controlled the weather．Chickens and other animals __6__
　　were sacrificed and their intestines poked to find signs
　　indicating rain and drought．Somewhat more scientific were __7__
　　predictions based on vegetation:"Onion's skin very thin ,mild
　　weather coming in．Onion's skin thick and tough, coming
　　weather is cold and rough．" Insects and animals were also __8__
　　favorite weather clues: "Before the glowworm lights his __9__
　　lamp，then the air is always damp ．" "If spiders their cobwebs
　　forsake，the weather will for certain break ．" "If frogs remained
　　in pools，the weather will be fine ．If they were seen on rocks, __10__
　　rain and cold were due．" It's difficult to say whether this rhyme
　　should be taken seriously : " Hark，I hear the asses bray ．Me thinks
　　we'll have some rain today ．"

　　答案及解析：
　　1．While—When或After
　　本句的this指代的是to change the weather by using magic．when/after 引导时间状语
　　2．in—than
　　earlier是early的比较级，其后应有than
　　3．those之后加who
　　who引导定语从句
　　4．删除advance前的the
　　in advance为习语
　　5．take—have
　　have connection with 为习语
　　6．controlled—controlling或在controlled前加that/which
　　controlling the weather 或that/which controlled the weather做定语修饰the actual factors
　　7．and—or
　　rain和draught只能是二者之一
　　8．删除is
　　与上文平衡，均为省略句
　　9．before—when/if
　　条件句
　　10．will—would
　　if 引导的是条件句用的是remained一般过去时