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北京地区某洁净室面积为250m2，层高3．0m；室内参数要求：t=(2±21)℃，φ=(50±5)％，洁净度等级[N]7级，室内热负荷60kW，人很少，ε→+∞，室内空气露点温度t1=12℃，送风温度t0=14℃，洁净室的送风量为________m3／h。
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建筑高度超过100m的建筑，宜采用________供水方式。
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{A. By; B. In; C. Until} 2050, the world's population {A. projected; B. is projected; C. has been projected} to rise to 9 billion from just over 7 billion currently. Proponents of genetically modified foods say they are safe and can boost harvests {A. even though; B. even; C. though} in bad conditions by protecting against pests, weeds and drought. This, they argue, will be essential to meeting the needs of a booming population in decades to come and avoiding starvation.
{A. Furthermore; B. Moreover; C. However} Doug Gurian-Sherman, senior scientist for the food and environment program at the Union of Concerned Scientists, an advocacy group, said genetic engineering for insect resistance has provided only a modest increase in yields since the 1990s and drought-resistant strains have only {A. modestly; B. modest; C. moderate} reduced losses from drought.
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THE COMPANY LEADING THE FUTURE OF FARMING
Here's a crazy idea: Combine bioprinting and tissue engineering to "print" animal products and tackle some of the planet's biggest problems. Animal farming, after all, accounts for about half of all human-caused greenhouse gases, taking place on one-third of the available, non-frozen land on Earth. All to feed people's appetites for 300 million tons of meat a year.
Modern Meadow is a Missouri-based startup that engineers tissues to create lab-grown edible meat, in a process that eliminates many of the negative environment effects associated with traditional livestock practices.
The company claims that by carefully layering mixtures of cells of different types in a specific structure, in-vitro meat production becomes feasible. It’s set a short-term goal of printing a sliver of meat around two centimeters by one centimeter, and less than half a millimeter thick, which is edible.
The company explains in a submission to the United States Department of Agriculture: “The technology has several advantages in comparison to earlier attempts to engineer meat in vitro. The bio-ink particles can be reproducibly prepared with mixtures of cells of different type. Printing ensures consistent shape, while post-printing structure formation and maturation in the bioreactor facilitates conditioning.”
However, it admits that the road ahead is strewn with difficulties. “The consumer acceptance of such products may not be without challenges. We expect it will first appeal to culinary early-adopter consumers and the segment of the vegetarian community that rejects meat for ethical reasons. With reduction in price, it can reach the masses with religious restrictions on meat consumption (people restricted to Hindu, Kosher, Halal diets) and finally populations with limited access to safe meat production.”
Whatever the final outcome, lab-grown edible meat is no longer in the realm of science fiction. It is coming.
1. Animal farming is responsible for the occurrence of greenhouse gases.{T; F}
2. Modern Meadow is a newly-started business which aims to make profits by producing lab-grown edible meat.{T; F}
3. The method Modern Meadow adopted to produce in-virto meat is by layering mixtures of cells of different types in a specific structure.{T; F}
4. There is no meat engineered outside living bodies before.{T; F}
5. This lab-grown meat has already widely received by the masses.{T; F}
(教材课文原文)
_DIARY OF A SPACE ZUCCHINI _July 1
Today Gardener and his crew will depart in their seed pod; the replacement crew is ready to {A. carry away; B. carry on; C. carry through} in their place. He is wearing his space suit undergarments. Not too stylish but {A. functional; B. nonfunctional; C. conjunctional}. He gave all of us an extra long smell. His nose twitched with the slightest tickle from the leaf hairs on little Zuc. He said that what will be is for the best. It has been a wonderful journey; one chapter is closing, another is {A. to be opened; B. open; C. opening}. He had tears in his eyes, not just a small drop at the corners but a pool that was making him {A. to blink; B. blinking; C. blink}. He reached up and {A. turned up; B. turned out; C. turned down} the light. In the frontier you should not be afraid of the dark.
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