某同学做“馒头在口腔中的变化”的实验，具体过程如下，回答有关问题：

请回答下列问题：
(1)为了证明“唾液对馒头有消化作用”，在2号试管的A处应加入____ ，与1号试管起____ 作用。
(2)为了证明“牙齿的咀嚼，舌的搅拌”对馒头有消化作用，应选用____ 两支试管进行对照实验。
(3)实验结果是____ 号试管中的物质遇到碘液不变蓝，原因是____ 。
(4)通过以上实验可知，口腔对淀粉既能进行____ 消化，又能进行____ 消化。

    Mike worked for the Canadian government.One day, he was 1 to learn more about wolves.Do wolves kill lots of caribou (北美驯鹿)? Do they kill people?

    They gave him lots of food and clothes and guns.Then they put him on a plane and 2 him to a far-away place.The plane put him down and went away.There were no houses or 3 in this place, but there were lots of animals and lots of wolves.

    There are many 4 stories about wolves.Wolves are said to like to kill and eat people.Mike remembered these stories, and he was afraid.He had his gun 5him all the time.

    Then one day, he saw a group of wolves.There was a mother wolf with four baby wolves.A father wolf and another male wolf, younger than him, lived with them.

    Mike watched these wolves every day.The mother was a very good mother.She gave milk to her babies.She gave them lessons about life.They learned how to 6 food.The father wolf got food for the mother.The young male wolf 7 the children.They were a nice, happy family—a wolf family! Mike did not need his 8 any more.In a short time, he got on well with the family.Mike 9 them for five months.He learned that many stories about wolves were not true.Wolves do not eat people, and they do not eat many large animals.And he also learned bad things about 10.It was men who killed many caribou and wolves.

    Later, Mike wrote a book about wolves.He wanted people to understand them and stop killing them.

如图所示，ABCD是一玻璃砖的截面图，一束光与AB面成30°角从AB边上的E点射入玻璃砖中，折射后经玻璃砖的BC边反射后，从CD边上的F点垂直于CD边射出．已知∠B=90°，∠C=60°，EB=10cm，BC=30cm．真空中的光速c=3×10⁸m/s，求：

①玻璃砖的折射率；

②光在玻璃砖中从E到F所用的时间．（结果保留两位有效数字）

魏格纳是从哪两个洲的轮廓吻合得到启发，而开始大陆漂移说的研究: （   ）