1820年，安培在科学院的例会上做了一个小实验，引起了到会科学家的兴趣．如图9-11，把螺线管沿东西方向水平悬挂起来，然后给导线通电，会发生的现象是    (    )

京沪高铁于2011年6月30日正式运营。高铁以其舒适安全快捷的性能，低于汽车的价格，给公路交通和民航交通带来了巨大的挑战。北京至上海的快运汽车票价最有可能作出的反应是（    ）

小麦的毛颖和光颖是一对相对性状（显、隐性分别由A、a基因控制），抗锈和感锈是另一对相对性状（显、隐性分别由B、b基因控制），控制这两对相对性状的基因均独立遗传．以纯种毛颖感锈植株（甲）和纯种光颖抗锈植株（乙）为亲本进行杂交，F₁均为毛颖抗锈（丙）．再用F₁与丁进行杂交，F₂有四种表现型，对每对相对性状的植株数目比例作出的统计结果如图：

“太平洋垃圾岛”位于美国加利福尼亚州与夏威夷之间的海域（副热带海区）。其形成的直接原因是（   ）

阅读下列短文，从下面每小题的A、B、C、D四个选项中选出最佳选项。

B

    A group of children meet in the library each week during lunchtime. They are famous as the Miss Margaret Fan Club. Every Thursday, the twelve members of the Miss Margaret Fan Club make their way to the study center in the back of the library.
    The first Thursday they met, Miss Margaret greeted them with a little talk.
    "Welcome to the first meeting of the writing club!" she said. "During the school year, we will meet here to work on story writing. At the end of the year, I will put all of your stories together in a book."
    Miss Margaret gave a pencil and two pieces of paper to each student.
    "Now, your first homework is to think of a character. Now, try to think about an interesting person. When you think of this person, write down all the details(细节)about him or her in your head. "