问题 选择题

生物形态结构总是与生长的环境相适应的.某地区春季低温潮湿,夏季高温干旱,生长着一种春、夏季叶型不同的植物,其叶型数据如下表.下列推断正确的是(  )

A.甲型叶生长在春季,利于光合作用

B.乙型叶生长在春季,利于光合作用

C.甲型叶生长在夏季,降低蒸腾作用

D.乙型叶生长在夏季,增强蒸腾作用

答案

环境中影响生物生活的各种因素叫环境因素,分为非生物因素和生物因素.非生物因素包括:光、温度、水、空气、土壤等.生物因素是指环境中影响某种生物个体生活的其他所生物.甲型叶表面积大,可以接受更多的阳光,适应生活在光照较弱春季;同时表面积大表皮厚度小,保水能力弱,蒸腾作用强,适合生长在低温潮湿的夏季.乙型叶表面积较小,接受光照较少,适合生长在光照强烈的夏季;表面积小表皮厚度大,保水能力强,蒸腾作用弱,适合生长在高温干旱的夏季.

故选A.

单项选择题 A1/A2型题
阅读理解

What do you want to be when you grow up? A teacher? A doctor? How about an ice-cream taster?

Yes, there really is a job where you can get paid to taste ice cream. Just ask John Harrison, an “Official Taste Tester” for the past 21 years. Testing helps manufacturers(制造商) to be sure of a product’s quality. During his career Harrison has been responsible for approving large quantities of the sweet ice cream— as well as for developing over 75 flavors .

Some people think that it would be easy to do this job; after all, you just have to like ice cream, right? No— there’s more to the job than that, says Harrison, who has a degree in chemistry. He points out that a dairy or food science degree would be very useful to someone wanting a career in this “cool” field.

In a typical morning on the job, Harrison tastes and assesses 60 ice-cream samples. He lets the ice cream warm up about 12℉. Harrison explains, “You get more flavor from warmer ice cream, which is why some kids like to stir it, creating ice-cream soup.”

While the ice cream warms up, Harrison looks over the samples and grades each one on its appearance. “Tasting begins with the eyes,” he explains. He checks to see if the ice cream is attractive and asks himself, “Does the product have the color expected from that flavor?” Next it’s time to taste!

Continuing to think up new ideas, try out new flavors and test samples from so many kinds of ice cream each day keeps Harrison busy but happy— working at one cool job.

1. According to John Harrison, to be qualified in the “cool field”, it is helpful to __________.

A. keep a diary of work

B. have a degree in related subjects

C. have new ideas every day

D. find out new flavors each day

2. What does Harrison do first when tasting ice cream?

A. He stirs the ice cream.                                B. He examines the color of the ice cream.

C. He tastes the flavor of the ice cream.            D. He lets the ice cream warm up.

3. Which of the following is probably the best title of the passage?

A. Tasting with Eyes              B. Flavors of Ice Cream

C. John Harrison’s Life          D. One Cool Job