【单选题】

Passage ThreeMany are aware of the tremendous waste of energy in our environment, but fail to take advantage of straightforward opportunities to conserve that energy. For example, everyone knows that lights should be switched off when no one is in an office. Similarly, when employees are not using a meeting room, there is no need to regulate temperature.Fortunately, one need not rely on human intervention to conserve energy. With the help of smart sensing and network technology, energy conservation processes such as turning off lights and adjusting temperature can be readily automateD、Ultimately, this technology will enable consumers and plant managers to better identify wasteful energy use and institute procedures that lead to smarter and more efficient homes, buildings and industrial plants.Until now, wires and cables for power and connectivity have limited the widespread adoption of sensor (传感器) networks by making them difficult and expensive to install and maintain.Battery-powered wireless networks can simplify installation and reduce cost.But their high power consumption and the corresponding need for regular battery replacement has made wireless networks difficult and costly to maintain. Nobody wants to replace hundreds or thousands of window sensor batteries in a large building on a regular basis.The promise of wireless sensor networks can only be fully realized when the wiring for both the data communication and the power supply is eliminateD、Doing so requires a true battery-free wireless solution, one that can utilize energy harvested directly from the environment. To facilitate the widespread deployment of wireless sensor networks, Green Peak has developed an ultra-low-power communication technology that can utilize environmental energy sources such as light, motion and vibration. This technology, employing on-board power management circuits and computer software to monitor energy harvesters and make the best use of harvested energy, enables sensors to operate reliably in a battery-free environment.Wireless sensor networks deployed in our offices and homes will have an enormous impact on our daily lives, helping to build a smarter world in which energy is recycled and fully utilizeD、These wireless platforms, equipped with advanced sensing capability, will enable us to better control our lives, homes and environment, creating a truly connected world that enables people worldwide to live in a more comfortable, safer, and cleaner environment. Batteries are not an ideal energy source for sensor networks because they ______.

A、have to be replaced from time to time
B．contain metals that pollute the environment
C．require automatic recharging
D．are difficult and costly to maintain