已知4amb3与﹣3a2bn是同类项,则m﹣n=( ).

题型:填空题

问题:

已知4amb3与﹣3a2bn是同类项,则m﹣n=(    ).

考点:同类项
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婴幼儿面颊、额部出现密集红斑、丘疱疹、水疱时应考虑()。

A.接触性皮炎

B.过敏

C.脓疱疮

D.婴儿湿疹

E.荨麻疹

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穿越剧,因其许多剧情与历史事实不符,而遭到学者批评。下列情节违背史实的是[ ]

A.秦始皇“焚书坑儒“

B.汉武帝派张骞两次出使西域

C.唐太宗鼓励商人用交子进行商品贸易

D.乾隆帝隆重招待回归祖国的土尔扈特部首领渥巴锡

题型:填空题

适当的磷素营养,能够使()

A、光合产物较多地转化为碳水化合物,烟叶总糖量增加

B、光合产物较多地转化为含氮化合物,烟叶总氮量、总烟碱量和蛋白质含量增加

C、C/N适宜

D、调制后烟叶光泽黄亮,油润丰满

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Tim Richter and his wife, Linda, had taught for over 30 years near Buffalo, New York—he in computers, she in special education. "Teaching means everything to us", Tim would say. In April 1998, he learned he would need a heart operation. It was the kind of news that leads to some serious thinking about life’s purpose.
Not long after the surgery, Tim saw a brochure describing Imagination Library, a program started by Doily Patron’s foundation (基金会) that mailed a book every month to children from birth to age five in the singer’s home town of Sevier, Tennessee. "I thought, maybe Linda and I could do something like this when we retire," Tim recalls. He placed the brochure on his desk, "as a reminder."
Five years later, now retired and with that brochure still on the desk, Tim clicked on imagination library. The program had been opened up to partners who could take advantage of book and postage discounts.
The quality of the books was of great concern to the Richters. Rather than sign up online, they went to Dollywood for a look-see. "We didn’t want to give the children rubbish," says Linda. The books-reviewed each year by teachers, literacy specialists and Dollywood board members-included classics such as Ezra Jack. Keats’s The Snowy Day and newer books like Anna Dewdney’s Llama series.
Satisfied, the couple set up the Richter Family Foundation and got to work. Since 2004, they have shipped more than 12,200 books to preschoolers in their area. Megan Williams, a mother of four, is more than appreciative "This program introduces us to books I’ve never heard of."
The Richters spend about $400 a month sending hooks to 200 children. "Some people sit there and wait to die," says Tim. "Others get as busy as they can in the time they have left.\

What can we learn from Tim’s words in the last paragraph

A. He needs more money to help the children.
B. He wonders why some people are so busy.
C. He tries to save those waiting to die.
D. He considers his efforts worthwhile.

题型:填空题

三七的止血有效成分为

A.三七皂苷

B.三七氨酸

C.三七黄酮A

D.齐墩果酸型皂苷

E.三七黄酮B

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