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问题 选择题

下列区分两种不同物质的方法不正确的是（　　）

A．用水区分NaCl与蔗糖

B．用MnO2粉末区分稀的双氧水与水

C．用燃着的木条区分空气与二氧化碳

D．用二氧化碳区分澄清石灰水与盐酸

答案

A、NaCl和蔗糖都易溶于水，现象相同，故A不能区分；

B、加入二氧化锰产生大量气泡（氧气）的是双氧水，无现象的是水，故B可以区分；

C、燃着的木条伸入到空气中燃烧现象无变化，伸入到二氧化碳中会熄灭，故C可以区分；

D、通入二氧化碳，变浑浊的是石灰水，无变化的是盐酸，故可以区分；

故选A

填空题

How many of us would temp for three years while we waited for the perfect job Not many of us, perhaps. But Wentworth Miller, the "Prison Break" star, said he chose to wait even longer time (1) he found the right job.
"Actually I think it might have been three or four years until I was lucky enough to get guest (2) on TV shows," said Miller, 34, who rose to international stardom (3) to "Prison Break" in 2006. That kind of patience and p will was portrayed in "Prison Break". Miller (4) engineering wizard Michael Scofield, who tries everything to break out of a Chicago (5) with his brother. Miller said he was fond of his character, (6) he said "exists in shades of grey".
Miller comes from a (7) of teachers. He said he didn’t seem fated for a career in the arts, (8) his passion for acting. After (9) from Princeton with an English degree, he moved (10) his parents’ request to Los Angeles to look for a stable life. He started (11) in a little company that made television movies. This (12) simply faxing, filing, walking the boss’ dog and going to the store for the boss’ lunch. Every weekend during the summer, Miller (13) go to the office (14) he didn’t have air-conditioning. "I would hang (15) in the conference room and set up camp and rob the company kitchen," recalled Miller.
(16) , Miller realized he still had questions about his choice. He decided to quit. But the boss said he was making a mistake and offered him a well-paid assistant position. "I eventually (17) that if I did the corporate job, it would be great if I was successful, but I would always wonder about the (18) . If I did the acting and was successful, I would never wonder (19) that job," he explained. He quit and temped (20) many people in the entertainment industry.
Now, he’s a hot star and has people coming up to him at film festivals saying, "Weren’t you the one who (21) to stand by the copy machine "
"That was tough, but I’m glad I have that perspective. Because now I’m at a point (22) big shots laugh at all my jokes and I think, You know, I got coffee for people like you for six years’. So I know what’s (23) , because I’ve seen the other side." But what if, when he was offered the corporate job, there had been more money "It was never about the (24) There’s a kind of excitement that comes along with acting. I can’t find it anywhere else. Even if I had to go back to temping, even if this is not the beginning of an amazing career, I would not (25) making that jum
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