Most plants can make their own food from s

题型:单项选择题

问题:

Most plants can make their own food from sunlight, (1) some have discovered that stealing is an easier way to live. Thousands of plant species get by (2) photosynthesizing, and over 400 of these species seem to live by pilfering sugars from an underground (3) of fungi(真菌). But in (4) a handful of these plants has this modus operandi been traced to a relatively obscure fungus. To find out how (5) are (6) , mycologist Martin Bidartondo of the University of California at Berkeley and his team looked in their roots. What they found were (7) of a common type of fungus, so (8) that it is found in nearly 70 percent of all plants. The presence of this common fungus in these plants not only (9) at how they survive, says Bidartondo, but also suggests that many ordinary plants might prosper from a little looting, too.

Plants have (10) relations to get what they need to survive. Normal, (11) plants can make their own carbohydrates through photosynthesis, but they still need minerals. Most plants have (12) a symbiotic relationship with a (13) network of what are called my corrhizal fungi, which lies beneath the forest (14) . The fungi help green plants absorb minerals through their roots, and (15) , the plants normally (16) the fungi with sugars, or carbon with a number of plants sharing the same fungal web, it was perhaps (17) that a few cheaters—dubbed epiparasites—would evolve to beat the system. (18) , these plants reversed the flow of carbon, (19) it into their roots from the fungi (20) releasing it as "payment.\

5()

A.others

B.the others

C.other

D.the other

考点:普通考研西医综合西医综合
题型:单项选择题

麦角新碱临床用于子宫出血和子宫复原而不用于催产和引产,是因为

A.作用比缩宫素强大而持久

B.作用比缩宫素弱而短,效果差

C.口服吸收慢而不完全,难以达到有效浓度

D.对子宫颈的兴奋作用明显小于子宫底

E.对子宫颈的兴奋作用与子宫底相似

题型:单项选择题

以下不是半抗原的是

A.青霉素

B.多肽

C.内毒素

D.甾体类激素

E.核苷

题型:单项选择题

处分抵押房地产所得金额的分配顺序为()。①偿还抵押权人债权本息及支付违约金;②扣除抵押房地产应缴纳的税款;③支付处分抵押房地产的费用;④赔偿由债务人违反合同而对抵押权人造成的损害;⑤剩余金额交还抵押人。

A.③②①④⑤

B.①②③④⑤

C.③①④②⑤

D.⑤④③②①

题型:单项选择题

被后人奉为婉约派正宗的著名词人是()。

A.苏轼

B.陆游

C.秦观

D.张孝祥

题型:单项选择题

人类的历史,就是灾难与发展共存的历史。尽管包括强烈地震、暴风橫行、疾病肆虐等许多灾难已经过去百年之久,它们给我们心灵所造成的创伤,依然在隐隐作痛。尽管在现有的科学水平下,人类还不可能对多数破坏性地震作出准确预报,当前的地震预报尚处于低水平的探索阶段。然而,人类正是在灾难面前和与灾难的搏斗中,不断地步入更高的文明时代——因为地震,我们不断发明更好和更先进的预测和预报仪器;因为瘟疫,我们发明了一种又一种的疫苗和新药。我们深信,无论怎样的灾难,都不能令人类退缩。灾难只能令我们思考,赋予我们更高级的头脑和更坚强的毅力。而人类,也在与灾难的斗争中,一步步走向新的文明。

从认识论角度,分析人类尚不能对多数破坏性地震作出准确预报的原因。

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