①在装置i的烧瓶A中装入饱和碳酸钠溶液，在烧杯B中装入水玻璃（硅酸钠溶液），可以证明非金属性：Cl＞C＞Si

②在装置i的烧瓶A中装入饱和碳酸钠溶液，在烧杯B中装入水玻璃（硅酸钠溶液），可以证明酸性：HCl＞H₂CO₃＞H₂SiO₃

③装置ii可以测定酸碱中和热

④装置iii在保护金属Fe，是牺牲阳极的阴极保护法

⑤装置IV可验证铁的吸氧腐蚀实验．

根据句意，用括号内所给单词的适当形式填空。
____ The maths problem is so difficult that few of the students can work it out_______ (easy).
____ Jim is a brave man. He always tells_________ (he) to calm down when he meets trouble.
____ Very few of people believe what the boy says because he is_________ (honest).
____ Everyone was very happy because of the famous writer’s _________ (arrive).
____ In the film, the soldiers were excited when they got their________(wife) letters.

（1）用10mL量筒量取液体如图1所示，请读出所量液体的体积数为____ mL．然后从中倒出一部分液体后，把量筒放平稳，俯视液体凹液面的最低处，读数为2.8mL，从量筒内倒出液体的体积____  4mL（填“＜”，“＞”或“═”）．

（2）某同学用空塑料饮料瓶做简易净水器，设计图如图2．为了获得较好的净水效果，请你帮他继续设计：小卵石、活性炭、石英沙应放在的位置是____ 　．

A．①小卵石、②活性炭、③石英沙  

B．①活性炭、②小卵石、③石英沙 

C．①小卵石、②石英沙、③活性炭 

D．①活性炭、②石英沙、③小卵石．

Wang Feng is a ____. I like his songs very much.

During the winter holiday, Ted learned ____ (skate) on the real ice.