题目

某林区发生中度火烧后，植被演替过程见下图。(1)与①相比，③中群落对光的利用更充分，因其具有更复杂的___________结构。(2)火烧15年后，草本、灌木丰富度的变化趋势均为____，主要原因是它们与乔木竞争时获得的___________。(3)针叶林凋落物的氮磷分解速率较慢。火烧后若补栽乔木树种，最好种植________，以加快氮磷循环。(4)用样方法调查群落前，需通过逐步扩大面积统计物种数绘制“种-面积”曲线，作为选取样方面积的依据。下图是该林区草本、Nowadays, millions of lonely singles are now going online instead. The World Wide Web is quickly becoming the world’s most popular matchmaker（媒人）.Singles are flocking（涌向）to the Internet mainly because their busy lifestyles leave them little time to look for a significant other. Using dating sites（约会网址）is quick and convenient. Many singles say the regular dating scene has just led them from one bad experience to another and are ready to try something else. Dating sites also make it easy to avoid someone you are not interested in. In the real world, however, ignoring someone you don’t like can be difficult.Despite all the advantages, online dating also presents its own set of problems. People aren’t always those who they declare to be in their online description. Safety is another concern. You are just likely to find a criminal online as you are Mr. or Miss Right.Online dating experts recommend following a few safety tips:Guard your personal information. Never give out your personal information online. This includes your last name, phone number, home address and place of work.Watch for red flags. Do any of the people you are chatting with make disrespectful comments? Do they try to control you? Do they give false information about themselves? If so, forget them!Meet in a safe place. When meeting someone in person, choose a public location with other people around.Following these tips and you might be able to find the person of your dreams.【小题1】According to the passage, many lonely singles don’t appreciate the regular dating scene because it is _____________.A．unpopularB．troublesomeC．convenientD．forgettable【小题2】The underlined words in the second paragraph “a significant other” means _______”.A．a true friendB．a matchmakerC．a marriage partnerD．a happy family【小题3】Which of the following is NOT a suitable place for meeting someone you get to know through the Internet for the first time?A．At his / her house.B．At the museum.C．At McDonald’s.D．At the bookstore.【小题4】From this passage, we can infer that ____________.A．there are mostly homely and unemployed people online B．the police had better find criminals onlineC．we can find love only through the dating sitesD．following safety tips ensures a safe online dating experience