问题 解答题

某校生物兴趣小组在查阅资料时发现,杏仁能杀死昆虫,可以作为自制毒瓶的毒剂.果真如此吗?他们决定自己动手进行探究.下面是他们的实验过程及结果.

①取250mL玻璃瓶2只,标号为A、B.在A瓶中放入15克捣碎的杏仁,加水浸湿,在浸湿的杏仁上放一张吸水纸,拧紧瓶盖,放置48小时后备用.B瓶中除不加杏仁外,其他条件与A瓶相同.

②48小时后,将10只0.3克重的蚱蜢平均分为两组,分别放入A瓶和B瓶,拧紧瓶盖.

③观察并记录蚱蜢的活动状态,结果如下表.

时 间

         蚱蜢的状态        

实验处理

60秒70秒80秒
A瓶:加入捣碎的杏仁,加水活跃不活跃死亡
B瓶:不加杏仁,加水活跃活跃活跃
请回答:

(1)在实验中,A瓶和B瓶除是否加入杏仁外,其他条件都相同,这样的实验叫做______.

(2)实验结果表明,杏仁______(能、不能)杀死昆虫.

(3)有人认为蚱蜢不是杏仁杀死的,而是玻璃瓶中缺少空气而“憋”死的,你认为是否可能?______.为什么?______.

(4)如果要你证明捣碎的杏仁只有加水后,才能起到毒剂的作用,则需要设置C瓶与A瓶进行对照,C瓶的实验处理是______.

答案

(1)对照实验是在研究一种条件对研究对象的影响时,所进行的除了这种条件不同外,其他条件都相同的实验,这个不同的条件,就是惟一变量.设置一组对照实验,使实验结果具有说服力.一般的对实验变量进行处理的,就是实验组.没有处理是的就是对照组.

(2)通过表中实验结果表明杏仁能杀死昆虫.

(3)A、B瓶条件的不同之处是:A加了杏仁,B瓶没加入,其他条件相同,B瓶的蚱蜢没有死亡,可以证明A瓶的蚱蜢是被杏仁杀死的.

(4)对照实验除了变量之外,其他条件相同.设置C瓶与A瓶进行对照,变量是加水,A加水,C不加水,就形成了对照.

故答案为:(1)对照实验    (2)能    (3)不可能  B瓶内的蚱蜢没有死亡(或有B瓶作对照,意思相近即可)    (4)加入捣碎杏仁,不加水(或除不加水以外,其他条件与A瓶相同,或其他合理答案)

单项选择题
阅读理解

A middle-aged couple from California got to the Pacific Ocean after a 4,900- mile-cross-country walk, becoming the first to backpack the American Discovery Trail by walking.

Marcia and Ken started the travel across 13 states, through 14 national parks and 16 national forests from Delaware and finally reached their destination a day nearly eight months later.

“We are sad that a great adventure is over. Now we just go home and do housework” said the couple, who went through cities, desert, mountains and farmland before reaching the Pacific alone.

They overcame deep snow in the East, a quicksand in Utah, close lightning strikes in the Mid- west and strong desert sandstorms in the West while averaging 22 miles a day and taking only four days off.But they enjoyed the French history of St.Louis and the beauty of the Colorado Rockies.   They particularly remember kindness of strangers they met along the way.

“Americans are truly warm-hearted and wonderful. We got to meet people that we would never meet in our daily living at home. It' s an amazing country.” Marcia said.

小题1:Which of the following is the most suitable title?

A.The first couple to backpack the Pacific Ocean alone

B.The first couple to cover a 4,900 mile cross-country walk

C.A husband-and-wife team suffered a lot during an adventure

D.A husband-and-wife team got much help during an adventure小题2:Which of the statements is TRUE?

A.The couple travelled across 16 states.

B.Their walk lasted nearly half a year.

C.They prefer housework to adventure

D.They took four days off during the travel小题3:We know that during the walk, the couple_________.

A.were worried about their housework

B.once covered 22 miles within four days

C.were treated warm-heartedly by strangers

D.met strong desert sandstorms in the East小题4:Which place do you suppose can replace the underlined word “destination”?

A.Delaware

B.Colorado Rockies

C.California

D.Pacific Ocean