首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
A、Dense plantings compete light with weeds. B、Dense plantings compete air with seeds. C、Dense plantings compete nutrition with s
A、Dense plantings compete light with weeds. B、Dense plantings compete air with seeds. C、Dense plantings compete nutrition with s
admin
2016-10-18
27
问题
Consider the fact that crops generally produce several hundred seeds from each plant. By comparison,(19)each weed plant can produce tens or even hundreds of thousands of seeds. And some buried seeds can survive up to forty years or even longer. Eradicating weeds means that you have to remove all the seeds and roots so the plants will not grow back. But birds or the wind can reintroduce them to the land. A more common way to deal with weeds is to control them enough so that the land can be used for planting. Chemical weed killers or natural treatments like corn gluten can suppress weed growth. Dense planting of a crop can also act as a natural control. One of the most common methods for suppressing weeds is dense planting.(20)A dense, competitive crop that quickly shades the soil will help suppress many weeds. The seeds need light to grow, so blocking the sun will reduce weed growth. Animals like sheep or goats eat weeds, so they can provide a biological control. Insects and other organisms can also act as biological controls.(21)Preventing the spread of weeds is an important part of weed management. Farm vehicles should be kept out of areas with weeds. If that is not possible, then clean off the equipment and your shoes when leaving. Another way to make use of weeds is to compost them. Heat is produced in the process of making organically rich compost to improve soil. The heat will kill many weed seeds. The same is true of seeds that pass through animals that graze on weeds.
Questions 19 to 21 are based on the passage you have just heard.
19. How many seeds can each weed plant produce at most?
20. How can dense plantings suppress weeds according to the speaker?
21. How to prevent the spread of weeds?
选项
A、Dense plantings compete light with weeds.
B、Dense plantings compete air with seeds.
C、Dense plantings compete nutrition with seeds.
D、Dense plantings compete space with seeds.
答案
A
解析
录音中提到,密植可以抑制杂草生长,因为杂草生长需要阳光,而密植可以遮蔽太阳,减少杂草得到的阳光。
转载请注明原文地址:https://kaotiyun.com/show/UeY7777K
0
大学英语四级
相关试题推荐
中国的饺子是春节最重要的食物之一。由于它们的形状类似于古代金银元宝(ingot),因此它们象征着财富。家人们会在除夕夜聚在一起来包饺子。他们会在一个饺子里藏一枚钱币,吃到它的人会在来年走好运。中国的饺子在其他节日也很受欢迎,因此它是中国文化传统的一部分。中
Writeashortessaybasedonthepicturebelow.YoushouldstartyouressaywithabriefaccountofCampusActivitiesandthene
RecentlytheBarbicanmuseuminLondonheldanexhibitioncalledtheRainRoom.Duringthetimethisexhibitionwasopen,myTwi
Shouldgirlsgotoschoolonlywithothergirls?Isitbetterforboystoattendallboys’schools?Educatorsatschoolforgirl
A、Shewon’thavedinneruntilfinishingthereport.B、Sheistoobusytohavedinnerwiththem.C、Shedoesn’twanttohavedinne
A、Hismajor.B、Highsalary.C、Hispreference.D、Histutor’sadvice.C细节题。根据对话可知男士慢慢意识到自己非常喜欢动物,甚至超过了对人的喜欢,也就是说男士对动物的喜爱使他成为了一名兽医。
Theygotooneoftheworld’smostprestigiousuniversitiesandpridethemselvesontheirsuperiorintellectbutalmosthalfof
Theygotooneoftheworld’smostprestigiousuniversitiesandpridethemselvesontheirsuperiorintellectbutalmosthalfof
TVLinkedtoLowerMarksA)Theeffectoftelevisiononchildrenhasbeendebatedeversincethefirstsetswereturnedon.Nowt
A、GetsomechangefromJane.B、Goandlookforapayphone.C、Usethewoman’sphone.D、Payforthephonecall.C本题实际上是“建议题”。答案规则
随机试题
冷饮企业应该设置生产卫生用室,其内部应设
子宫于数天内急剧增大,呼吸困难,不能平卧,听不到胎心,诊断为急性胎儿窘迫。()
发展目标一般包括()。
根据《中华人民共和国商标法》第3条第1款规定,经商标局核准注册的商标为注册商标,商标注册人享有商标()权,受法律保护。
企业向银行或其他金融机构借入的各种款项所发生的利息均应计入财务费用。()
股权投资基金的合格投资者是指具备相应风险识别能力和风险承担能力,投资于单只股权投资资金的金额不低于100万元,且符合相关标准的单位和个人。下列符合相关标准的是()。
Ioftendreamofateacher,Idreamofstandingonthe【M1】______platformintheclassroomandgivelessonstolovelyboys【M2】
钙需求的推荐量是根据人体每天从汗液、尿液等途径损失的钙量,同时考虑钙的吸收效率估算出来的。欧美国家的推荐标准是青少年每天1300毫克,成年人每天1000毫克,而老年人则是1200毫克。不过WHO/FAO联合专家组指出这个标准是基于欧美人群的,并不一定适用于
A、Joiningaclub.B、Usingatimer.C、Puttingthecomputerinthelivingroom.D、Notspendinghoursuninterruptedly.A
HelpYourselfthroughtheHardTimesEveryone,atsomepoint,willsufferaloss—thelossoflovedones,goodhealth,oraj
最新回复
(
0
)