问题 填空题

下面是某兴趣小组探究教室里是否有细菌和真菌的实验方案,请你帮助设计完成.

材料用具:1号和2号装有牛肉汁培养基的培养皿(已高温灭菌)、透明胶带、放大镜

(1)提出问题:洗手前和吸收后手指上的细菌和真菌不一样吗?

(2)作出假设:______.

(3)制订计划并实施:

①1号培养皿的处理方法:______.2号培养皿不做处理,在实验中起______作用.

②把两个培养皿放在______的地方.

(4)观察结果,得出结论:

①1号培养皿的现象:______.

②2号培养皿的现象:______.

③你的结论是______.

通过实验可知,细菌和真菌适合于生活在______环境中.

(5)细菌和真菌的菌落不同,你如何来区分?______.

答案

(2)作出假设:教室的空气里有细菌和真菌.

(3)制定并实施计划:

①打开1号培养皿,暴露在教室空气中5~10分钟是接种.1号培养基与2号培养基对照,实验变量是接种,1号培养基是实验组,2号培养基是对照组.

②对照实验设计原则:一个探究实验中只能有一个实验变量,其他因素均处于相同理想状态,这样便于排除因其他因素的存在而影响、干扰实验结果的可能.把两个培养皿放在相同适宜条件下培养.

(4)观察结果,得出结论:分析结果①1号培养皿有多种菌落形成,②2号培养皿无菌落形成.得出结论③说明教室的空气里有多种细菌和真菌.由此可知,细菌和真菌适合于生活在营养丰富、温度适宜等环境中.

(5)人们可以利用菌落的不同形态特点,初步区分细菌和真菌.细菌菌落特征:菌落较小,形状:表面或光滑黏稠,或粗糙干燥,易挑起,多为白色;真菌落特征:菌落较大,比细菌菌落大几倍到几十倍、形状:菌丝细长,菌落疏松,呈绒毛状、蜘蛛网状、棉絮状,无固定大小,多有光泽,不易挑,有时还呈现红色、褐色、绿色、黑色、黄色等不同的颜色(孢子的颜色).

故答案为:(2)教室的空气里有细菌和真菌; (3)制定计划并实施:①打开培养皿,暴露在教师空气中5~10分钟,再盖上,封好;②对照;③相同适宜条件下培养; (4)观察结果,得出结论:①有多种菌落形成;②无菌落形成.③教室的空气里有多种细菌和真菌;营养丰富、温度适宜.(5)可以利用菌落的不同形态特点,初步区分细菌和真菌

问答题
单项选择题

Millions of Americans and foreigners see GI.Joe as a mindless war toy, the symbol of American military adventurism, but that’ s not how it used to be. To the men and women who (1) in World War I1 and the people they liberated, the GI. was the (2) man grown into hero, the pool farm kid torn away from his home, the guy who (3) all the burdens of battle, who slept in cold foxholes, who went without the (4) of 1hod and shelter, who stuck it out and drove back the Nazi reign of murder. This was not a vohmteer soldier, not someone well paid, (5) an average guy, up (6) the best trained, best equipped, fiercest, most brutal enemies seen in centuries.

His name is not much. GI. is just a military abbreviation (7) Govermnent Issue, and it was on all of the article (8) to soldiers. And Joe A common name for a guy who never (9) it to the top. Joe Blow, Joe Magrae... a working class name.The United States has (10) had a president or vieepresident or secretary of state Joe.

GI. Joe had a (11) career fighting Geman, Japanese, and Korean troops. He appears as a character, or a (12) of American personalities, in the 1945 movie The Story of GL Joe, based on the last days of war correspondent Ernie Pyle. Some of the soldiers Pyle (13) portrayde themselves in the fihn. Pyle was famous for covering the (14) side of the warl, writing about the dirt-snow-and-mud soldiers, not how many miles were (15) or what towns were captured or liberated. His reports (16) the "willie" cartoons of famed Stars and Stripes artist Bill Maulden. Both men (17) the dirt and exhaustion of war, the (18) of civilization that the soldiers shared with each other and the civilians: coffee, tobacco, whiskey, shelter, sleep. (19) Egypt, France, and a dozen more countries, G. I. Joe was any American soldier, (20) the most important person in their lives.

6()

A.for

B.into

C.form

D.against