问题
单项选择题
屏蔽β射线首选（）
A.铅
B.铝
C.有机玻璃
D.水泥
E.铁
答案
参考答案：C
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屏蔽β射线首选（）
A.铅
B.铝
C.有机玻璃
D.水泥
E.铁
参考答案：C
| 完形填空。 | ||||
| Serious Business Let me take you 1 a couple of years.Come with me as we relearn a lesson, one that has stuck with me, in my present memory, and 2 me yet. We walked into Elida Road Hardware, an old-fashioned hardware store.No automatic door, not a computer in the building.It was one that I went to fairly often.As we entered the door, two sounds 3 us. The sleigh bells of last year made that sweet, peaceful tinkle as we opened the door.The other sound was the electronic beeper that reminded Andy of our 4 . "Good afternoon, Ryan," 5 the cheerful greeting.Andy was a very 6 sort of owner. He was of medium build and height, and the smile on his face welcomed us. We walked across the old wood floor.Andy asked us what he could help us with.I told him we were 7 a spring.He very patiently replied, "I have lots of springs.You're going to need to be more 8 ." "Just a spring for an old-fashioned screen door." "That's it.A screen door spring.Right down there." We 9 where he was pointing, and sure enough, there they were.Andy knew his store, and his products.That was why I came here instead of Meijer. The service couldn't be beaten. The price -Yes.But service and 10 -No. I picked up one and followed him to the 11 . He 12 the price, doing the math in his head."$ 1.88 , with tax: comes to $ 1. 99. " " Put it on my dad's account." He nodded and smiled, "Good dad's account." He laughed."I don't know what you boys would do 13 dad's account!" He handed me the ticket and as I 14 it I asked, "You really trust my signature?" His reply surprised, 15 delighted me."When I can't trust Jerry Hoover's boys I can trust nobody!" We left, and the brain 16 started to forget things, in order of importance.But what Andy said that day rang in my ears.And it rings in my ears today.That's a tall order to live up to. It's a high standard of 17 . My father made a fame for that name, and I get to 18 the benefits.But on account of this, I must 19 that fame. And that's 20 business. | ||||
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