现有浓度为10%的标准混合气气样，要求配制浓度为0.5%的混合气样2

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问题单项选择题

现有浓度为10%的标准混合气气样，要求配制浓度为0.5%的混合气样2000ml，应取该标准混合气气样（）ml。

A、100

B、200

C、300

D、400

答案

参考答案：A

填空题

根据所给的首字母填写单词。

Today is the twins Nick and Lily's birthday. T 1 are twelve. Amy, Millie, Peter and Bill are the

twins' f 2 . They want to buy some things f 3 them. There is a big s 4 near their school. There are

a l 5 of nice things there. From the shop, people can buy some f 6 , some drinks and some school

t 7 . The shop is o 8 from 8.00 a.m. to 7.00 p.m., so they can buy things on their way h 9 . They buy

a big cake, two pencil boxes, an orange teddy bear, a m 10 plane and some nice notebooks.

填空题

《渔业捕捞许可证》、渔船主机功率凭证和《渔业船网工具指标批准书》由（）规定样式并统一印制。