问题 问答题 简答题

柑桔黄龙病的危害是什么?如何防治?

答案

参考答案:

柑桔黄龙病是芸香科柑橘属和金柑属植物的重要病害,其病原菌为韧皮部杆菌属细菌,寄生于韧皮部,系统侵染但分布不均。始发病呈现“黄梢”症状,叶片黄化、早落,再发梢短、叶小;病树不长新根,有的根部腐烂、大量枝条坏死;果实畸形、味淡、易早落,失去商品价值。幼树发病后一般1-2年内枯死,成年树发病后3-5年内枯死或丧失结果能力。

主要防治措施:

(1)严格检疫。禁止未经检疫的柑橘苗木和接穗进入新区和无病区。

(2)种植经检疫合格的无病健康苗木。

(3)防虫控病。在春芽萌动期和每次新梢抽发期,及时施药防治柑桔木虱。

(4)挖除病树。对柑桔黄龙病株一经确认即坚决挖除集中烧毁,挖除前要先喷药杀灭病株及其周围植株上的柑桔木虱。

(5)加强栽培管理。合理施用氮磷钾肥,多施有机肥,增强树势,统一控梢。

阅读理解

任务型阅读理解。

     We always seem to want those things we don't have. Moreover, we are often convinced (使相信) that if

we had those things we want so badly, we would finally be happy.

     The truth is that happiness is an attitude(态度). _________is not something created by outside

circumstances(环境), ______ instead is completely within your control.

     Nothing will give you a deep sense of satisfaction and happiness, unless you cultivate (滋养)happiness

consciously. Below are some simple yet specific steps you can take to cultivate happiness.

     Be grateful.

     Create a sense of gratitude for what you have, for what is working, for what is wonderful and sweet in

your life. A morning or evening gratitude list, written each day, can do wonders for helping you feel grateful.

     Take care of yourself.

     Identify(辨别) the small things in life that make you feel good, and do one daily. A short walk, a few

minutes of writing in your journal, a short meditation, watching the sunset…whatever, will improve your

outlook on life.

     Read inspirational(励志的) material.

     It helps to be reminded of positive thoughts and positive attitudes. Get a small book of positive, inspirational

thoughts and keep it by your desk. Read one or two thoughts each day.

      Is the glass half empty or full? Life works better when the glass is half full regardless of your life status.

     No matter how many wonderful things you do to create a positive, happy, satisfied life, you could still end

up unhappy. Ultimately, happiness, gratitude, a feeling of satisfaction is a choice. So, from now on, choose to

be happy!

1. 在划线出填入所缺单词:___________ ___________

2. How many ways can we take to cultivate happiness?

________________________________________________________________________

3. 将短文中划线的句子译成汉语.

________________________________________________________________________

4. 找出同义句:We are sure if we can have the thing we want so much,we will be very happy.

_________________________________________________________________________

5. 找出文章的主题句

______________________________________________________________________

单项选择题