Many people traveled to Las Vegas, Nevada last week for the 50th Consumer Electronics Show, or CES. The show is said to have the largest collection of new electronic devices in the world.

    The show had many examples of “smart home” devices. “Smart home” technology is designed to make life easier for people by letting computers control many things inside our homes. One such device actually begins working outside the home, when someone arrives and rings the doorbell.

    “When someone comes to your front door and rings the doorbell, the light can turn on immediately. I get a notification when I'm halfway around the world that someone came, and I can start talking to the person who's at my front door, and I can say, 'Oh, here let me let you in,' I can unlock the door for them very easily.” Said Vivint, a smart home service provider.

    One electronics maker launched a device that lets people see and interact with their animals when they are away. The device, from Petcube, lets you remotely watch and talk to your pet through a personal device, according to a company official. It can even give the pet a treat—if you approve and order it.

    For heating or cooling, there is a smart thermostat. This device can also send you a message if a big storm causes leaks of flooding. “We're trying to catch it with just a few drips before it becomes a real big problem,” said Mike Sale of iDevices.

    A concern for many homeowners is the possibility that someone else might find a way to attack these smart home devices. An official from Vivint said his company is sure that only owners of the home can gain use of information on the devices. Warren Katz from iDevices said his company employs engineers from the defense industry to help prevent hacking.

小敏学习了“光的折射”后，想知道光进入不同介质时，弯曲程度是否相同（折射角是否相等），如不同，弯曲程度与什么因素有关.老师帮她设计了下面的实验：

用一厚玻璃缸盛一定量的水，让一激光手电筒射出的光束从空  气中斜射入水中，从水中再进入玻璃，然后再进入空气中，其光路图如图所示.小敏还上网查出了一些介质的其他参数，如下表：

读图完成下列要求。