测定铁制品中铁的质量分数
铁是常用的金属材料,兴趣小组的同学对某铁制品中的质量分数进行测定.称取3g铁屑,缓慢加入一定溶质质量分数的硫酸溶液,直到过量(假设除铁以外的物质都不与硫酸反应),实验数据如图所示.

请计算:
⑴
⑵
⑶
⑷
⑸
A. doctor B. teacher C. parents D. cook E. study
⑹
⑺
⑻
⑼
⑽
F. glasses G. long hair H. bedroom I. big eyes J. bathroom
.
的公式。一种情形是x的大小与y、z都有关;另一种情况是x虽然可由y、z计算,但与y、z无关。下列四个公式中,属于前一种情形的是( )
B . 密度ρ=
C . 比热容c=
D . 电流I=
—About 30 minutes.
B .
C .
D .

For centuries, Beijing has been one of China's most important cities. 1a place for emperors and officials, today it is an international city and a popular tourist2. People from all over the country are moving to Beijing to 3 jobs and opportunities as this exciting city is a place where dreams can come true. Throughout the city, 4 dressed business people 5for their offices, mobile phones held to their ears and visitors can only watch and imagine the deals and 6being made at that very second.
Beijing's streets provide a fascinating 7of the past and the present. In tea houses, groups of old men play chess 8the Macdonald's next door is filled with laughing teenagers sipping milkshakes. Walking through the broad streets 9with designer stores and multi-storey skyscrapers, you can 10 a turn and suddenly find yourself in a century's old 11 where a fruit seller chats happily to an old woman sitting in the sun. Many of the road signs and advertising billboards are now in 12, making Beijing more 13to foreigners. Public transport is efficient, new businesses are14, and every modern convenience and international brand is15in this booming global city.
Beijing has some of China's most stunning 16. Visitors often come to Beijing with the single 17to see the Great Wall, one of the ancient wonders of the world, but once they've arrived, they realize that this is only one of the city's 18. In fact, what visitors ever seem to only19about Beijing, is that they simply20time before seeing it all.
p是.下面是人体呼吸系统、循环系统及泌尿系统的部分结构示意图,分析回答问题:
