蜘蛛有8只脚，蜻蜓有6只脚和两对翅膀，蝉有6只脚和一对翅膀，现_爱下问搜题

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问题解答题

蜘蛛有8只脚，蜻蜓有6只脚和两对翅膀，蝉有6只脚和一对翅膀，现有这三种小虫共18只，共有脚118只，翅膀20对．求每种小虫的只数．

答案

根据题意，可得蜘蛛的只数是：（118-6×18）-（8-6）=5（只）；

那么蝉和蜻蜓的只数是：18-5=13（只）；

再根据题意可得，蜻蜓的只数是：（20-1×13）÷（2-1）=7（只），

则蝉的只数是：13-7=6（只）．

答：蜘蛛5只，蜻蜓7只，蝉6只．

完形填空

15-year-old Tom reached school, waiting outside his classroom for his classmates to .It was a cold,wet day. Tom stared at the . Then his eyes fell upon the 18-metre-high hill that   at the back of the classroom.
He   large amounts of rainwater flowing down the hill, and water was also bubbling(冒泡) at the base of a rock on the hill. For a few minutes, Tom    the water, wondering why it looked so    . Then it hit him — the    was similar to the video he was shown during Disaster Management classes. Fearing a   disaster, he shouted    at the students waiting outside their classrooms. “Run, run, don't stay here! The   on the hill is going to fall on us!”
Chaos broke out as the    ran to the open area that had been appointed as an emergency gathering point. When some teachers   Tom, he showed them the water gushing from the hill, and they started leading the students to safer ground.
Just then Principal Richard drove into the school. Tom ran over to tell him what was happening. After   the site, Richard knew the school was in   . The enormous rock at the top of the hill could come crashing down   .
a group of teachers and older students, Richard climbed the hill and tried to make the water flow away from the rock. They were too   : ten minutes later, they heard screams as the huge rock rushed down the hill. There was little Richard and his group could do as they watched the earth    their classrooms. Thanks to Tom’s   action and careful observation,   was hurt in the incident.

D．interesting

A．for the moment

C．at one time

D．at any minute

判断题

灭火战斗行动是指消防指战员在灭火战斗中的各项行动。