如图所示的两种剪刀，正常使用时属于省力杠杆的是_____剪刀（填_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题填空题

如图所示的两种剪刀，正常使用时属于省力杠杆的是_____剪刀（填甲、乙）；如图所示，是表示人肱二头肌收缩使前臂曲肘的情况，图中已标出了支点的位置，桡骨及茶杯的受力方向。从图上可知人的前臂是一个杠杆（选填“省力”、“费力”或“等臂”），这种结构给人带来的好处是。

答案

甲费力省距离

题目分析：从图中可以看出甲剪刀的动力臂大于阻力臂属于省力杠杆，乙剪刀的动力臂小于阻力臂属于费力杠杆，人的前臂是费力杠杆，费力杠杆的好处是省距离。

单项选择题 A1型题

鉴于食源性寄生虫病对人类健康的危害，我国规定，在生猪屠宰中，必检的寄生虫是（）

A.肉孢子虫

B.弓形虫

C.并殖吸虫

D.圆线虫

E.旋毛虫

完形填空

"What's it like to have a gap between your teeth?" a girl asked me one day.
Nobody had ever _. 36 _ before. My hand unconsciously rose to cover my mouth. But, as she looked at me, sincerely waiting for__ 37__, 1 realized she was not trying to be rude. "I never think about it," I truthfully replied. She nodded and turned away. I was left wondering if people _38__ me and saw only gappy teeth.
Later that day at home, I began to __39 __ my teeth again. I felt upset. I thought my life would be somehow better if my teeth were not gappy. How I wanted the perfect teeth that everyone else seemed to have!
Of course, Mom   40 everything . She has lived her entire life with gappy teeth, and tried to convince me that there was nothing to __41__. When I refused to listen, she told me I could get the surgery to close the gap if it was that important. "Let's be   42__, though," she said. "If everyone got surgeries to become pretty, everyone would be exactly the same. There is beauty in differences."
Her __43__ made me consider my teeth seriously. The thought of losing my gap was more terrible than the reality that people were going to notice it. I realized how important it was to me. It is part of my 44 _.
Nowadays many people do ridiculous things to realize their dream of "perfection." The__45_ is that no one is perfect. When all potential for ugliness is removed, so is all of the potential for   46__.
So if that girl ever asked about my teeth   47___, I would truthfully answer. "You know? It's really cute."

C．a suggestion

C．talked about

A．worry about

A．possibility