对维持生物圈中氧气和二氧化碳的平衡起重要作用的生理活动是
A．绿色植物的光合作用
B．绿色植物的呼吸作用
C．绿色植物的蒸腾作用
D．动物的呼吸作用
答案：A
题目分析：绿色植物在光合作用中制造氧，超过了自身呼吸作用对氧的需要，其余的氧气都以气体形式排到了大气中；绿色植物还通过光合作用，不断消耗大气中的二氧化碳，这样就维持了生物圈中二氧化碳和氧气的相对平衡，简称碳-氧平衡．生物体利用氧气，将体内的有机物分解成二氧化碳和水，同时释放出能量的过程叫做呼吸作用，是一切生物的共同特征；植物体内的水分以气体状态从体内散发到植物体外的过程叫做蒸腾作用，蒸腾作用能够降低植物体的温度，促进植物根对水和无机盐的吸收和运输，对植物的生活具有重要的意义，因此与生物圈中碳-氧平衡有关的生理作用是光合作用．
故选：A
Every year mobile phones develop. Imagining what they will look like and be able to do in 2020 is really a challenge. To help, experts have outlined three major mobile trends that they believe will have become reality by then. Our phones will be so smart in 10 years’ time that they’ll know everything about our situation and warn us when something needs our attention. This is the top prediction of both Nokia and Google. They predict that our cars and home appliances will be able to communicate with our mobile. For example, fridges will tell your mobile to tell you to pick up milk on the way back from work. While driving, your mobile will suggest that you take a different route because there’s a road accident up ahead. The second trend is in gesture-based controls. People who know the iPhone’s touch-sensitive screen are already familiar with the technology. It translates hand movements into actions on-screen. But gestural communications will make the phone more convenient to use and may completely replace touchpads. According to industry insiders, the most immediate step forward in gestural technology will be in voice recognition. It’s believed voice recognition technology will speed up communications. It is quicker to speak than type. Eventually, phone screens will disappear. The third major development will change our understanding of a mobile phone. From a single phone, the mobile will be developed into multi-part devices. It is opposite to the current trend in which mobile phones are combining the functions of cameras, music players and game consoles. The prediction is based on the idea that the world will become more wireless and all these—cameras, music players and game consoles—will be wirelessly connected. Mobile phones won’t need to contain these devices because users will be able to control them wirelessly through their phones. 小题1:The first paragraph serves as .
小题3:From the text, we can learn that the future mobile phones will .
|
