问题 实验题

显微观察时,常制作临时装片。下图是制作人体口腔上皮细胞临时装片的过程图和显微镜的结构图,请据图回答问题:

(1)正确的操作步骤是:                  (2分)

(2)在步骤B中滴加的液体是                 

(3)是盖盖玻片操作。正确的方法是:用镊子夹起盖玻片,使它的一边先接触       上的水滴,然后缓缓放下。这样做可以避免盖玻片下面出现         而影响观察。

(4)用显微镜观察制作好的临时装片,在镜下已经找到观察物,如果视野中光线过暗,应调节[   ]          和[   ]           ;如果要使物像更清晰些,应调节[    ]               

答案

(1)DACEB(2)生理盐水(3)载玻片;气泡(4)③遮光器;⑦反光镜;⑥细准焦螺旋

题目分析:(1)制作人的口腔上皮细胞临时装片方法步骤:

1、用洁净的纱布把载玻片和盖玻片擦拭干净.

2、用滴管在载玻片的中央滴一滴生理盐水

3、用消毒牙签在自己漱净的口腔内侧壁上轻轻地刮几下.

4、把牙签上附有碎屑的一端,放在载玻片上的生理盐水滴中涂抹几下。

5、用镊子夹起盖皮片,使它的一边先接触载玻片上的水滴,然后缓缓地放下,盖在要观察的材料上,这样才能避免盖玻片下面出现气泡而影响观察.

(2)制作洋葱表皮临时装片和口腔上皮细胞临时装片滴的液滴不同,前者滴的是清水,后者滴的是生理盐水,都是为了维持细胞的正常形态。

(3)盖盖玻片操作。正确的方法是:用镊子夹起盖玻片,使它的一边先接触载玻片上的水滴,然后缓缓放下。这样做可以避免盖玻片下面出现气泡而影响观察。

(4)实验中调节显微镜视野的明暗程度,我们用遮光器和反光镜,如果光线较暗,应该用大光圈和凹面镜,如果光线较强,应该用小光圈和平面镜;调节细准焦螺旋能使物象更加清晰;

阅读理解

Win a trip to the OREGON COAST-Dare to Explore the Pacific Ocean. Build the biggest sand castle on the beach. Search tide pools for sea life. Watch the bright orange sunset over the ocean. Whether you’ve been to the Pacific Ocean before or have only closed your eyes and imagined it, we want to know how you would explore the Oregon Coast if you had the chance to go this summer.

JUDGING

1. Clear relationship between the Essay and the Drawing 40%

2. Creativity and skill in design and form of the Drawing 40%

3. Expression of the passion to draw and explore 10%

4. Journalistic quality, tidy nature and overall quality of the Essay 10%

PRIZE

By entering, you will have the chance to win an all expense paid trip to the ORECON COAST. Activities will include: kite flying, studying beautiful sea creatures, searching for sea life in a boat, science exploration at a science center and roasting over a beach campfire.

Who may enter: The competition is 0pen to kids aged 6 - 14.

TERM :  Entries(参赛作品) must be postmarked no later than July 31 ,2009.

How to enter

Surf travelogue. com/kids to download and print out an entry form.

Be sure to mark whether you have or have not been to the Pacific Ocean in山e form. Create a drawing of the Pacific Ocean on a piece of paper using a pen or paints.

Write an article of 100 words or less to explain why you want to go, what you think you would see and what you would explore if you have never been to the Pacific Ocean, or describe your favorite memories from your last visit.

Send to Dare to Explore the Pacific Ocean. NG1145 14th street NW. Washington D. C. 20036

72. What is the most important for the judging?

A. Whether your article is written in a neat way. 

B. The article and the drawing should be closely related.

C.Whether you show your passion to draw and explore

D. The skill in your drawing the map of the AtlanticOcean.

73. If you win the competition, you may____

A. fly a kite on the beach          B. search the beach for sea plants

C. roast the sea creatures over a beach campfire 

D. win an all expense paid trip to Washington D. C.

74. What information can you get from the passage?

A. Your article should be 8t least 100 words.

B. Every kid can rake part in the competition.

C. You must send the drawing before June 31, 2009.

D. Your entry form should be downloaded and printed out.

75. You can most probably read the passage in ________ .         .

A.a textbook B.a travel guide     C.a newspaper D.a research book

问答题