But astronomers can't use it whenever they like; they have to bid for time on the already over-burdened instrument. After about 2010, when the aging Hubble starts to fail, astronomers won't be able to go to it at all. That's why space watchers are always looking for clever ways to take super-clear images from the ground without the blurring of the atmosphere. And it's why a recent piece of news from Cambridge University and Caltech made scientists take notice. By wedding a new electronic light detector to the Hale Telescope in California, astronomers were able to snap at least one space photo that was literally twice as sharp as a comparable Hubble image and 50,000 times cheaper. The concept behind the detector (探测器), which is known, cutely, as the Lucky Camera, is very simple: The earth's altering atmosphere acts as a lens, which changes moment by moment as pockets of warmer or cooler air constantly pass in front of a given object. That's why stars blink and why telescopes on the ground can be only so sharp. The stars blink for the Lucky Camera too. So the computer that runs the Lucky Camera saves those rare, perfect images instead of the rest. And because a single 1⁄20-second exposure of an object in space is almost invisible, the computer combines the good images and produces one that could be used. Still, the Lucky Camera isn't a true replacement for the Hubble. Since it has to throw away most of its images, it isn't very efficient. Yes, it took a picture sharper than the Hubble could, but it took a lot longer. The instrument is also limited to a patch of sky only about 1⁄120th the width of the full moon; the Hubble's field of view is 150 times as large. And the Hubble can see ultraviolet (紫外线) and infrared (红外线) light, which the atmosphere blocks. Ultimately, says Mackay, "we're not competing with the Hubble. We're simply trying to provide another choice when the Hubble dies."1. Why can't the Hubble satisfy the need of astronomers?A) Because it has been overburdened and becomes unavailable. B) Because it flies too far away for astronomers to go onto it.C) Because it is too expensive and aging.D) Because it is too complicated and always fails in function.2. Which of the following best describes the difficulty of taking super-sharp images from the ground?A) The climate changes from time to time so there is not enough sunshine.B) Stars blink from time to time so it is difficult to catch the sight of them.C) Warmer air or cooler air changes the function of the lens of the telescope.D) The atmosphere changes from time to time so the images of the objects in space are distorted. 3. How does the Lucky Camera work?A) It takes pictures with a detector in space and produces a combined one.B) It takes many pictures on the ground and produces a combined one.C) It takes many pictures of the space and selects the best ones. D) It takes pictures with a wide field of view and produces the largest one.4. Which of the following is true about the Lucky Camera?A) It is very efficient in taking supper-clear pictures.B) It has a wider field of view than the Hubble.C) It can see ultraviolet light.D) It takes sharper pictures than the Hubble could. 5. According to the passage, the Lucky Camera is a(n) ________ of the Hubble.A) competitorB) replacementC) backup choice D) improved version

For taking super-sharp pictures of space, the best telescope is the Hubble, in orbit above the earth. But astronomers can't use it whenever they like; they have to bid for time on the already over-burdened instrument. After about 2010, when the aging Hubble starts to fail, astronomers won't be able to go to it at all.  That's why space watchers are always looking for clever ways to take super-clear images from the ground without the blurring of the atmosphere. And it's why a recent piece of news from Cambridge University and Caltech made scientists take notice. By wedding a new electronic light detector to the Hale Telescope in California, astronomers were able to snap at least one space photo that was literally twice as sharp as a comparable Hubble image and 50,000 times cheaper.  The concept behind the detector (探测器), which is known, cutely, as the Lucky Camera, is very simple: The earth's altering atmosphere acts as a lens, which changes moment by moment as pockets of warmer or cooler air constantly pass in front of a given object. That's why stars blink and why telescopes on the ground can be only so sharp. The stars blink for the Lucky Camera too.    So the computer that runs the Lucky Camera saves those rare, perfect images instead of the rest. And because a single 1⁄20-second exposure of an object in space is almost invisible, the computer combines the good images and produces one that could be used.  Still, the Lucky Camera isn't a true replacement for the Hubble. Since it has to throw away most of its images, it isn't very efficient. Yes, it took a picture sharper than the Hubble could, but it took a lot longer. The instrument is also limited to a patch of sky only about 1⁄120th the width of the full moon; the Hubble's field of view is 150 times as large. And the Hubble can see ultraviolet (紫外线) and infrared (红外线) light, which the atmosphere blocks. Ultimately, says Mackay, "we're not competing with the Hubble. We're simply trying to provide another choice when the Hubble dies."1. Why can't the Hubble satisfy the need of astronomers?A)  Because it has been overburdened and becomes unavailable. B)  Because it flies too far away for astronomers to go onto it.C)  Because it is too expensive and aging.D)  Because it is too complicated and always fails in function.2. Which of the following best describes the difficulty of taking super-sharp images from the ground?A)  The climate changes from time to time so there is not enough sunshine.B)  Stars blink from time to time so it is difficult to catch the sight of them.C)  Warmer air or cooler air changes the function of the lens of the telescope.D)  The atmosphere changes from time to time so the images of the objects in space are distorted. 3. How does the Lucky Camera work?A)  It takes pictures with a detector in space and produces a combined one.B)  It takes many pictures on the ground and produces a combined one.C)  It takes many pictures of the space and selects the best ones. D)  It takes pictures with a wide field of view and produces the largest one.4. Which of the following is true about the Lucky Camera?A)  It is very efficient in taking supper-clear pictures.B)  It has a wider field of view than the Hubble.C)  It can see ultraviolet light.D)  It takes sharper pictures than the Hubble could. 5. According to the passage, the Lucky Camera is a(n) ________ of the Hubble.A)  competitorB)  replacementC)  backup choice D)  improved version