题干

如图表示某植物叶片暗反应中C3和C5化合物微摩尔浓度的变化趋势,该植物在Ⅰ阶段处于适宜环境条件下,Ⅱ阶段改变的环境条件是降低光照强度或者降低CO2浓度中的某一项。下列分析正确的是(     )

A:图中物质甲转变成乙需要消耗光反应提供的ATP

B:图中Ⅱ阶段所改变的环境条件是降低了光照强度

C:Ⅱ阶段甲上升是因为叶绿体中H和ATP的积累

D:若CO2浓度降低,Ⅱ阶段光合速率最大时所需光照强度比Ⅰ阶段低

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D

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    Workers aren't allowed to go into a big underground computer center until they step up to a machine that takes a quick picture of the tiny blood vessels (血管) inside their eyes.

    If the machine can't 1 the picture with images in its computer, the worker is stopped by security guards (保安员).

    Each person has his own way of blood vessels in his or her2.And unlike a key, the way can't be3.Old-fashioned keys and locks may soon be things of the past.High-tech security devices (安全装置) are being fixed at military (军事的) bases, computer centers and banks.Companies that 4 the machines say they'll someday be used in people's homes and cars.

    Already, a Japanese company has fixed ways that recognize (识别) people's fingerprints in 360 new homes.The machines open the doors only for the 5of the houses.The new security ways are selling well because thieves and robbers are getting better at breaking into buildings and computers that are 6 by keys and locks.Since nobody can steal or copy a fingerprint, or one's eyes, the new machines are 7.

    Other new machines recognize one's voice.Two American companies use 8 machines to keep an eye on their computers.Inexpensive voice-recognition machines may someday take the place of locks on cars.The doors would open only for the owners.The machines would 9 the owners as little as $270.Although the up-to-date machines are amazing, scientists must still solve a serious problem.How will a boy borrow his dad's car without borrowing his dad's 10?