Question

【題目】 An INTERESTING experiment

It takes a little skill to do this experiment, but the result is truly SURPRISING.

What do you need? Several rubber balloons Wooden skewer（木簽） Vegetable oil Paper towel		Step l Blow up a balloon, let some of the air out of it, and tie it closed.
		Step 2 Rub some oil on skewer with paper towel.
		Step 3 Gentle twist（搓捻）and push skewer into end of balloon opposite the knot. If balloon pops（爆 炸），go back to Step 1.
		Step 4 When skewer is in balloon, slowly twist and push it out of balloon near knot.
What will happen?		28 The balloon does not pop, even though it has a skewer in it.
Why won't it pop?	Rubber is made out of long chains of molecules （分子）. The skewer pushes these molecules aside. The molecules mix with the oil and they stick together tightly. The oil on the skewer seals the hole and air cannot get out.

【1】Which is the most suitable word for 28 ?

A.TopicB.ResultC.ProblemD.Reason

【2】What’s the proper meaning of the underlined word "seals"？

A.密封B.潤滑C.點燃D.腐蝕

【3】What can we infer（推斷）from the passage?

A.It's easy to push a skewer into and out of a balloon.

B.You'd better blow as much air as possible into a balloon.

C.There's no need for you to use the oil while doing the experiment.

D.It's hard for the air to get out of the hole as molecules and oil stick together.

Answer 1

【答案】

【1】B

【2】A

【3】D

【解析】

本篇介紹“氣球不爆裂”這個實驗所需的器材、實驗的步驟、實驗的結(jié)果并分析原因——長鏈分子與油混合在一起并緊緊地粘在一起，堵住了洞口，氣球才不會漏氣。

【1】

推理判斷題。根據(jù)文中“The balloon does not pop, even though it has a skewer in it.” ——即使氣球里面有一根木簽也不爆裂；可知這句是實驗的結(jié)果，故選B。

【2】

詞義猜測題。由實驗結(jié)果可知，即使氣球里有一根木簽，也不會爆裂；根據(jù)“Rubber is made out of long chains of molecules. The skewer pushes these molecules aside. The molecules mix with the oil and they stick together tightly.”——解釋氣球不爆裂的原因是長鏈分子與油混合在一起并緊緊地粘在一起，封住了洞口，氣球才不會漏氣；故選A。

【3】

推理判斷題。根據(jù)文中“The molecules mix with the oil and they stick together tightly. The oil on the skewer seals the hole and air cannot get out.”可知由于分子和油粘在一起，空氣很難從洞里出來，故選D。