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
专升本
It takes a long time to grow a tree. How long? Well, pine trees are the quickest growing trees, but still, they take twenty year
It takes a long time to grow a tree. How long? Well, pine trees are the quickest growing trees, but still, they take twenty year
admin
2011-06-28
19
问题
It takes a long time to grow a tree. How long? Well, pine trees are the quickest growing trees, but still, they take twenty years to reach a size suitable for cutting and harvesting. An oak takes about sixty years to grow to a good size. A redwood may take hundreds of years.
Lumber companies, which make their money on trees, depend on those that grow quickly. There- fore, they are always looking for methods to make trees grow faster. So far, the secret to fast growing trees seems to lie in "super-seeds." These are seeds that are gathered from the quickest growing trees in a forest. One company searched 100,000 acres of trees and selected the seeds from just fifteen trees. These two ounces of seed were enough to plant several hundred new trees. Eventually, when these trees have grown, seeds will again be taken only from the fastest growing trees of crop. This process of artificial selection will yield, in the future, a super-tree that will grow in half the time it takes normal trees to develop.
Unfortunately, it takes a long time for a plan like this to reach its goal. The Weyerhauser Lumber Corporation, which started its first collection of seed in 1958, is just now beginning to harvest the super-seeds of the first generation of the faster growing trees.
This selection centers on______.
选项
A、the life span of trees
B、the age of redwoods
C、making trees grow quickly
D、cutting trees for lumber
答案
C
解析
全文讲了如何才能使树木成长得快一点。Life span寿命。选项c是正确的。
转载请注明原文地址:https://jikaoti.com/ti/Jn3GFFFM
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
Americansenjoyfastfoodmainlybecause______.Accordingtothetext,adrive-inwindowis______.
______experienceofworkinginanofficeenvironmentisessentia[forthisjob.
China’semploymentandre-employmentsituationremainstoughwithasurgethisyearinthenumberofgraduateshittingthejobm
Ifyouplaywithelectricity,youmaygetanelectric______.
Theauthorthoughtofhisfiend’squestionasagoodone,because______.Fromthepassage,wecanlearnthattheauthor’satti
Theauthorthoughtofhisfiend’squestionasagoodone,because______.Inthelastparagraph,"thisverybasicfact"refers
IcanclearlyrememberthefirsttimeImetMr.Andrews,myoldheadmaster,【C1】______thatwasovertwentyyearsago.Duringthe
WhatcanyoudotorecallyourdreamsmoreoftenandinterpretthemmoreClearly?Theexpertsofferthesesuggestions:Devel
Billy,ahard-workingstudent,isfourteenyearsoldandintheninthgrade.Hehasapart-timejobthat【C1】______himupeverym
Billy,ahard-workingstudent,isfourteenyearsoldandintheninthgrade.Hehasapart-timejobthat【C1】______himupeverym
随机试题
A.22℃左右B.72℃左右C.55℃左右D.94℃左右E.100℃左右引物的延伸温度是
A.气虚血少B.气虚血瘀C.气虚出血D.气随血脱E.血虚气亏气摄血功能失常可见
()将“安全第一、预防为主”规定为我国安全生产管理的基本方针。
(2007年)单元体的应力状态如图5—50所示,若已知其中一个主应力为5MPa,则另一个主应力为()MPa。
生态影响预测包括( )。
击打式打印机中,最普遍使用的是喷墨打印机。()
增一个一级部门,部门编码为“99”,部门名称为“立信服务中心”。
从迁移实质看,迁移是新旧经验的整合过程,整合的实现方式不包括()
设非负函数f(x)当x≥0时连续可微,且f(0)=1.由y=f(x),x轴,y轴及过点(x,0)且垂直于x轴的直线围成的图形的面积与y=f(x)在[0,x]上弧的长度相等,求f(x).
Everyoneknowsthatthefirstruleofdrivingisnevertakingyoureyesofftheroad.Teendrivers【C1】______beingcareful,butt
最新回复
(
0
)