单选题The underlined word "fragile" in the last paragraph is closest in meaning to ______.

单选题Which of the following is an example of the third form of cooperation as it is defined in Paragraph 4?

单选题Nothing has ever equaled the ______ and speed with which the human species is altering the physical and chemical world.

单选题A pigment called melanin protects the ______ layers of skin from sun rays. A. under B. below C. underlying D. underneath

单选题Jupiter ______ perhaps the most important planet of the solar system. A. was B. were C. is D. will be

单选题ssing the last bus, we had no choice but ______ a taxi home. A. to take B. take C. taking D. taken

单选题Because everyone knows, facts speak louder than words. A. Since B. That C. It D. As

单选题There are many different ways of comparing the economy of one nation with those of another.

单选题Contrary______what people generally believe, men, not women, need encouragement more. A．upon B．beside C．to D．at

单选题Critics of the Wright brothers thought that the idea of a flying machine was totally {{U}}preposterous{{/U}}.

单选题Some of the low-end made-in-China mechanical-electronic products are not selling well in export market as compared with what are termed as high-end ones. A. on export market B. in exporting market C. in exported market D. in the export market

单选题Having finished lunch, the case was discussed.

单选题Opposite the square is a very tall building,______top is well above the tops of the others. A. its B. whose C. which D. that

单选题The police let him go, because they didn't find him guilty ______ the murder.

单选题I'll take down your name and address in case you______as a witness.

单选题Seeing______pictures, she couldn't help thinking of______happy days in______ ViennA．

单选题The pictures of the Loch Ness Monster show a remarkable resemblance to a plesiosaur, a large water reptile of the Mesozoic era presuming extinct for more than 70 million years.

单选题Roger Federer Lights up the Arabian Night 罗杰·费德勒点亮阿拉伯之夜 Plenty of people will be glad Tim Henman was not here to trouble Roger Federer once more last night，as the seedings said he should have been.Popular with the expatriates though he may be，and capable of upsetting Federer though he undoubtedly is，there is nothing quite so stirring as seeing one of the most gifted world No l s of all in full cry. Instead of struggling with his jinx player，Federer imposed a spell of his own.He beat Andrei Pavel，whom Henman beat in the Paris Masters final，by6-3，6-3，and strode the court like a ruler who knows his aura is expanding. It carried the Swiss imperiously into a semi-finals of the Dubai Championships，where he will face Jarkko Nieminen.The Finn earned his place by defeating the Dutch No 8 seed Sjeng Schalken 6-3,6-3. Federer insisted he was not at his best-"I haven't wanted to chase the fines as much as I should，"he said. Pavel was driven to distraction as it was.He had akeady lifted himself near the level he showed when he was in the top 20.But just when he looked as if he might prolong the second set， Federer struck. He retrieved one ball from deep，outside the tramlines on the forehand side，turned and reached the next ball from short and outside the tramlines on the backhand side，and still somehow hit a controlled winner.It completed the decisive break of serve. Pavel responded by launching a spare ball towards the sky and it landed on the whiskey tables in the lrish village below.The umpire uttered a code violation warning in little more than a whisper.It was as though he felt sympathy for the Romanian. If Federer reaches tomorrow's final he will play Spain's Feliciano Lopez，whose Davis Cup debut came in the singles in the 2003 final in Melbourne，or Mikhail Youzhny，whose first Davis Cup experience was as a ball boy in the 1995 final in Moscow. That spurred Youzhny to make a top-level breakthrough seven yearslater，and to develop perseverance which has been revealed this week in a 6-3，1-6，6-1 quarter-final win over Rafael Nadal yesterday in heat which would have made a camel protest，and in a recovery from two days'vomiting after eating Japanese seafood."My cap felt as if it weighed five kilos."he said.

单选题While many studies indicate that remotely sensed data provide cost-effective and up-to-date information in managing earth resources, use of the Utremendous/U amount of already available data in meaningful applications has not reached its full potential.

单选题The trapeze artist who ran away with the clown {{U}}broke up{{/U}} the lion tamer's heart.