方案一：Cu $\stackrel{O_2}{\underset{△}{\to }}$ CuO $\stackrel{稀硫酸}{\underset{△}{\to }}$ CuSO₄

方案二：Cu $\stackrel{浓硫酸}{\underset{△}{\to }}$ CuSO₄ Cu+2H₂SO₄（浓） $\frac{\underset{\_}{△}}{}$ CuSO₄+SO₂↑+2H₂O

比较上述两个方案，你认为方案一的优点是

①节约能源  ②不产生污染大气的二氧化硫  ③提高硫酸的利用率 ④提高铜的利用率（   ）

Everybody ______ fun! （  ）

请根据句意从方框中选择合适的单词，并用其适当形式填空，使句子通顺。

 (1)Look! They are watching the film Lost in Thailand with ____  on the Internet.

(2)My father's ____  birthday happens to be on Father's Day.
(3)The Internet is____  used in most families in our country today.
(4)Those beautiful paintings don’t belong to us. They are those____ .
(5)It will make you feel ____  if you sit too long in front of the computer.