【单选题】下列实验设计及其对应离子方程式均正确的是( )
A.
用浓盐酸酸化的KMnO 4 与H 2 O 2 反应,证明H 2 O 2 具有还原性:2MnO -4 +6H + +5H 2 O 2 ═2Mn 2+ +5O 2 ↑+8H 2 O
B.
Na 2 O 2 与H 2 O反应制备O 2 :Na 2 O 2 +H 2 O═2Na + +2OH - +O 2 ↑
C.
稀盐酸滴在石灰石上:CO 2-3 +2H + ═CO 2 ↑+H 2 O
D.
用FeCl 3 溶液腐蚀铜线路板:Cu+2Fe 3+ ═Cu 2+ +2Fe 2+
【判断题】2018 年度某外籍专家在中国工作,居住了 70 天,在中国任职期间的工资 20000 美元,其中 10000 美元中方直接支付。另外 10000 美元中方转交其本国派出公司支付。外籍专家应就其中方支付的 10000 美元在中国缴纳个人所得税。
【简答题】Australia is the smallest continent(洲) in the world. It is a little smaller than China. It is near the south of the equator(赤道).So when it is summer in our country, it is winter in Australia. Australi...
【单选题】关于能源,以下说法中不正确的是()
A.
煤、石油、天然气等燃料的最初来源都可追溯到太阳能
【单选题】产品成本是指企业生产是生产者为生产一定种类和数量的产品所消费的( )。
【简答题】阅读理解。 Australia is the greatest island in the world. It is a little smaller than China. It is to the south of the equator (赤道). So when it is hot summer in our country, it is cold winter in Australia....
【单选题】产品成本是指企业生产是生产者为生产一定种类和数量的产品所耗费的()。
【单选题】产品成本是指企业生产者为生产一定种类和数量的产品所消费的( )。
【单选题】Why does the woman like Luxor better than Cairo?
A.
Because it is a little town.
B.
Because it is free from pollution and good for shopping.
C.
Because it is convenient for shopping.
【简答题】阅读理解。 Australia is the largest island in the world. It is a little smaller than China. It is in the south of the earth. Australia is big, but its population is small. The population of Australia is ne...