题目内容
Which of the following is NOT mentioned as a means by which an orchid attracts insects？
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To lure their pollinators from afar, orchids use appropriately intriguing shapes, colors, and scents. At least 50 different aromatic compounds have been analyzed in the orchid family, each blended to attract one, or at most a few, species of insects or birds. Some orchids even change their scents to interest different insects at different times.
Once the right insect has been attracted, some orchids present all sorts of one-way obstacle courses to make sure it does not leave until pollen has been accurately placed or removed. By such ingenious adaptations to specific pollinators, orchids have avoided the hazards of rampant crossbreeding in the wild, assuring the survival of species as discrete identities. At the same time they have made themselves irresistible to collectors.
The orchid is unique because of______.
PART C
Directions: You will hear three dialogues or monologues. Before listening to each one, you will have 5 seconds to read each of the questions which accompany it. While listening, answer each question by choosing A, B, C or D. After listening, you will have 10 seconds to check your answer to each question. You will hear each piece ONLY ONCE.
听力原文： The piano and violin are girls' instruments. Drums and trumpets are for boys. According to Psychologists Susan O'neil and Michael Bottome, children have very clear ideas about which musical instruments they should play. They found that despite the best efforts of teachers, these ideas have changed very little over the past decade. They interviewed 153 children, aged between 9 and 11, from schools in northwest England. They asked them to identify four musical instruments and then say which they would like to play most and which they would least like to play. They also asked the children for their views on whether boys or girls should not play any of the four instruments. The piano and violin were both ranked more favorably by girls than by boys, while boys preferred the drums and trumpets, There was a broad agreement between boys and girls on which instruments each sex should play and the masons varied. And while almost half of all boys said they avoided certain instruments because they were too difficult to play. Only 15 percent of girls gave that as a reason. Earlier studies indicated that very young school children aged between 5 and 7, showed no bias in choosing musical instruments. But their tastes become more clear between the ages of 8 and 10. One survey of 78 teachers suggested that after that age, both boys and gifts begin to restrict themselves to the so-called male or female instruments.
How many children did Susan and Michael interview？
According to the passage, new stars are formed in spiral galaxies due to______.
听力原文： Born in 1879, in Ulm, Germany, Einstein was two years old when his parents moved to Munich. There his father opened a business in electrical supplies. As a boy, Einstein did not learn to talk until later than others of his age, and in his early childhood he was not considered especially bright. But by the time he was 14 years old, he had taught himself advanced mathematics from textbooks. By them he knew what he wanted to be when he grew up. He wanted to be a physicist and &vote himself to research.
Einstein could not afford to pay for the advanced education he needed, because his family business had declined. Later, he and his family were forced to leave Munich to live in Milan, Italy, where they had relatives. As for him, the family did manage to send him to a technical school in Switzerland, and later to the Federal Institute of Technology in Zurich. In 1901, when Einstein was 22 years old, he began teaching, and in 1902, be went to work as a patent office examiner in Bern. Now able to pay his own expenses, he continued his schooling at the University of Zurich, where he received a doctor's degree in 1905. This was the period when he first began the research, which led to his famous theory of relativity.
Toward the end of his life, when Einstein was asked to explain his law of relativity to a group of young students, he said, "When you sit with a nice girl for two hours, you think it's only a minute. But when you sit on a hot stove for a minute, you think it's two hours. That is relativity."
What is Einstein's greatest contribution to human beings？
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