Siri. The intelligent assistant that helps you get things done. All you have to do is ask. 
Now you can use your voice to use your iPhone 4S. Just talk to Siri as you would to a person: “Do I need an umbrella?” or “Where’s the closest ATM?” Siri not only understands what you say, it knows what you mean. It figures out the right apps to use to find the right answer. Then, just like a personal assistant, it answers you. Siri makes phone calls, sends messages, schedules meetings, sets reminders, and more. How much more? Just ask, and Siri tells you that, too.
Dual-core A5 chip: the most powerful iPhone ever. 
Two cores in the A5 chip provide up to two times more power and up to seven times faster graphics. And you’ll feel the effects. iPhone 4S is quick and responsive, which makes all the difference when you’re launching apps, surfing the web, gaming, an doing just about everything. And no matter what you’re doing, you can keep on doing it. Because the A5 chip is so power-efficient, iPhone 4S has outstanding battery life.
FaceTime. It’s even better face-to-face.
FaceTime of iPhone 4S lets you hear a voice and see the face that goes with it—iPhone to iPhone, iPad 2, iPod touch, or Mac over Wi-Fi. So no matter where they are, no matter where you are, you’ll always be there. Making a FaceTime call is just as easy as making a phone call. And it’s even easier with Siri. Just tell Siri “FaceTime with Mom” and you show up, smile and wave hello. You’ll never miss a big event, an important meeting or a good laugh. And who wouldn’t be happy to see your face?
小题1:The passage is mainly about __________.
A．how to use iPhone 4S
B．some models of iPhone 4S
C．some special uses of iPhone 4S
D．how to understand some pictures小题2:What is special about Siri?
A．It can take photos.
B．It can make videos.
C．It can write messages.
D．It can answer questions.小题3:Which of the following helps iPhone 4S to perform fast?
A．
B．
C．
D．
小题4:Which of the following is NOT TRUE about FaceTime?
A．It can be used together with Siri.
B．It allows you to see the other person’s face.
C．It allows you to hear the other person’s voice.
D．It can only be used between iPhone and iPhone.
，在同一双缝干涉装置中a光的相邻亮条纹间距小于b光的相邻亮条纹间距，说明λa＜λb，则：fa＞fb，因此水对a光的折射率比b光的大，故选项C正确；肥皂泡呈现彩色条纹是光的干涉现象造成的，故选项D错误。