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 ."
答案详解：
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