题干

如图表示有限环境中某一种群增长的曲线。下列有关叙述正确的是
①K值是环境条件所允许达到的种群数量最大值
②在K值时,种群的增长率最大
③如果不考虑迁入迁出等其它因素,在K值时出生率等于死亡率
④假设这是鱼的种群,当种群达到K值时开始捕捞,可持续获得最高产量

A:①②

B:①④

C:①③

D:②③

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C

同类题2

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    HEARST CASTL, CA

    Hearst Castle is open for tours daily, except Thanksgiving, Christmas and New Year's Day.

    Tour A -- The Grand Rooms

    View the ground floor rooms of La Casa Grande where Mr. Hearst's guests met their host and were entertained during their stay. See the Assembly Room, where guests met for cocktails, the Refectory, where meals were served, the Morning Room, Billiard Theater. Your knowledgeable guide will bring this big house to life sharing stories about Mr. Hearst, his many guests, and the art collection it contains.

    Prices: Adults: $25.00; Children: $12.00.

    Tour B – The Upstairs Suites (套房)

    This tour features rooms on the upper floors of Casa Grande. Travel through guest suites on your way to the Library where Mr. Hearst housed a collection of 2,000-year-old Greek pots.

    Visit Mr. Hearst's private third floor suite including his bedroom and private study where he held business meetings. Learn about the genius of architect Julia Morgan and the way she put Mr. Hearst's art collection into the design.

    Prices: Adults: $20.00; Children: $10.00.

    Tour C – Evening Tour

    This tour allows visitors to experience the Castle at night as a visitor to the Castle in the 1930s might have. It features highlights from the experience, Upper Floors of Casa Grande, and Garden tours.

    Evening tours are offered on most Fridays and Saturdays during March – May & October – December.

    Prices: Adults: $36.00; Children: $18.00.

    Tour D – Accessible Holiday Twilight

    This tour is wheelchair accessible. Visitors who have difficulty climbing stairs, or who cannot stand or walk for extended period, may also benefit from this tour. Accessible transportation is provided from the Visitor Center to all areas of the Holiday at Hearst Castle tour. Call 866-712-2286 for additional information.

    Prices: Adults: $30.00; Children: $18.00.

同类题5

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。

    Taking good notes is a time-saving skill that will help you to become a better student in several ways ____.Second, your notes are excellent materials to refer to when you are studying for a test. Third, note-taking offers variety to your study time and helps you to hold your interest.

    You will want to take notes during classroom discussions and while reading a textbook or doing research for a report. ____ Whenever or however you take notes, keep in mind that note-taking is a selective process. ____

    The following methods may work best for you.

●Read the text quickly to find the main facts and ideas in it.

●Carefully read the text and watch for words that can show main points and

supporting facts.

● Write your notes in your own words.

____

● Note any questions or ideas you may have about what was said or written.

    As you take notes, you may want to use your own shorthand(速记). When you do, be sure that you understand your symbols(符号) and that you use them all the time. ____

A.Use words, not complete sentences.

B.There are three practical note-taking methods.

C.You must write your notes on separate paper.

D.Otherwise, you may not be able to read your notes late

E. you will also want to develop your own method for taking notes.

F. That means you must first decide what is important enough to include in your notes.

G. First, the simple act of writing something down makes it easier for you to understand and remember it.