问题 问答题 论述题

试述“积温学说”的内容和积温在农业生产中的应用及其局限性。

答案

参考答案:

“积温学说”认为作物在其它因子都得到基本满足时,在一定的温度范围内,温度与生长发育速度成正相关,而且只有当温度累积到一定总和时,才能完成其发育周期,这个温度的总和称为积温。它反映了作物在完成某一发育期或全生育期对热能的总要求。

应用方面:

A、用活动积温作为作物要求的热量指标,为耕作制度的改革、引种和品种推广提供科学依据。

B、用有效积温等作为作物的需热指标,为引种和品种推广提供重要科学依据。

C、应用有效积温作为预报物候期和病虫害发生期的依据,等等。

局限性:积温学说是理论化的经济方法。事实上在自然条件下作物的发育速度是多因子综合作用的结果。如作物的发育速度不单纯与温度有关,还与光照时间、辐射强度、作物三基点温度和栽培技术条件等因子有关。

阅读理解

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

Active listening is an essential skill in learning. It is when you listen carefully to make sure you understand and learn the information that is being conveyed.     小题1:  Here are some things which can help you to listen actively.

   小题2:   . Don’t just write everything down. Listen carefully and make sure you understand what the purpose of this lecture is. As you take down notes, keep the main point in mind and make sure you understand how these notes are related.

◆Listen for an organizational structure. Listen carefully to figure out how the ideas are organized and they will make more sense.

◆Pay attention to organizational cues (暗示).    小题3:   Pay close attention to the introduction, as it will probably show how you should organize your notes. If the lecture begins with, “Today I’m going to talk about three ethnic conflicts (种族冲突) in the Middle East,” then you have a good idea of what’s going to follow. Listen for “signpost” words to show a transition (过渡) from one point to the next, such as “next” and “finally” and numerical signposts like “first” or “third”.

◆Listen with your eyes.   小题4:   Watch the teacher and be aware of how he or she uses hand gestures, eye contact and other body language to convey points.

◆Remove distractions. Put away the campus newspaper, your cell phone and anything else that might be more interesting than the lecturer.

Learning to concentrate and listen actively is an endurance(耐力) skill.   小题5:  

A.Speakers communicate information through nonverbal communication.

B.Unfortunately, many students don’t know how to listen actively when they attend classes.

C.If your teacher indicates that something is important, mark it.

D.Make yourself do it, and it will get easier over time.E. Listen carefully for words and phrases that reflect the organizational structure of the lecture.

F. Your teachers’ notes are probably organized into some kind of outline.

G. Listen for the main point and major sub-points.

单项选择题 配伍题