问题
填空题
设MP和OM分别是角
①MP＜OM＜0；②OM＜0＜MP；③OM＜MP＜0；④MP＜0＜OM， 其中正确的是______（把所有正确的序号都填上）． |
答案
由MP，OM分别为角
的正弦线、余弦线，如图17π 18
∵sin
=MP＞0，cos17π 18
=OM＜0，17π 18
∴OM＜0＜MP．
故答案为：②．
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设MP和OM分别是角
①MP＜OM＜0；②OM＜0＜MP；③OM＜MP＜0；④MP＜0＜OM， 其中正确的是______（把所有正确的序号都填上）． |
由MP，OM分别为角
的正弦线、余弦线，如图17π 18
∵sin
=MP＞0，cos17π 18
=OM＜0，17π 18
∴OM＜0＜MP．
故答案为：②．
| 完形填空。 | ||||
| eBooks still some way away from students Twelve-year-old Tang Yin is one of the earliest students to test a digital textbook in China. The boy said he was a little 1 when he received the monochromatic (单色的) flat device in April, 2010, because he thought it should be a " 2 cool" laptop. But Tang still cherishes (珍爱) his new equipment like "protecting my 3 ," said the fifth grader. After all, not every student has the opportunity to 4 the eBook, which is worth 2,000 yuan, he said. The 50 eBooks, 5 by Taiwan eBook manufacturer Chuanqi Photoelectric Technology in Yangzhou, Jiangsu Province, enable one class at Yangzhou Sanyuanqiao Elementary School to be the 6 group of students in the Chinese mainland to replace their regular textbooks with electronic ones. Out of l,000 students, Tang' s class was the lucky 7 . "Our school could not 8 the project without the company' s donation," said Yuan Shishan, vice-headmaster of the primary school 9 the digital book is considered environmentally friendly, because it replaces paper books and saves money in the long run, the price is much higher than most Chinese 10 can afford. Also, some technical defects, the 11 of taking notes and monochromatic display, make the eBook fail to meet the expectations of students and teachers. "There's still a(n) 12 way to go before the eBook really plays an important role in education," said the headmaster. According to Yuan, the annual average income of a 13 family in Yangzhou is about 20,000 to 30,000 yuan, and neither the parents nor the school can afford the 2,000 yuan 14 book. The school doesn't allow the students to take their eBooks to their homes. The devices are 15 after class, and are locked in the headmaster's office. | ||||
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