问题
单项选择题
利用电磁波进行无线电通信时，电磁波的频率是由（）决定的。
A、天线
B、话筒
C、检波器
D、振荡器
答案
参考答案：D
搜题请搜索小程序“爱下问搜题”
利用电磁波进行无线电通信时，电磁波的频率是由（）决定的。
A、天线
B、话筒
C、检波器
D、振荡器
参考答案：D
完形填空（共20小题；每小题1分；满分20分） My name is Amy. I’m a 25-year-old graduate student who likes yoga, home-decorating shows and eating spoonfuls of peanut butter 1 from the jar. Oh yeah, and I’m an iPhone addict. I wasn’t always an addict. In fact, for many years I told myself I didn’t want a 2 cellphone. They seemed like too much work, always beeping, ringing and 3 attention. I was 4 content with my simple antique (古董，此处指旧手机), and I didn’t expect to change my mind any time soon. However, about a year ago, I found myself envious of all those proud iPhone owners, cradling their shiny new phones and 5 all their friends. I started listening secretly to conversations about “iPhone apps”, feeling like a 6 listening to a language I couldn’t speak. Eventually I couldn’t 7 my iPhone instinct (本能) any longer, and I welcomed my new iPhone into my life. To my surprise, I suddenly found myself with a whole new circle of friends. They 8 my iPhone-related inquiries when my other friends couldn’t, and didn’t 9 when I bragged about (吹嘘) all the things little Eloise (yes, I named her) could do. However, I realized I had a problem when one day I found myself Google-mapping my way to my mailbox, which happens to be right outside my front door. When I 10 the past few months, I couldn’t believe I didn’t see this coming. All the 11 signs were there. Eloise slept right beside me and was the first thing I 12 in the morning. I 13 my e-mail about 20 times a day. I also experienced 14 when I left poor Eloise in the change room at the gym. 15 she beeped and needed my response? Okay, so I was addicted to my iPhone. I decided 16 had to be done. But, as I quickly realized, iPhones are like 17 and not easy to quit. Then, while taking the bus to work one day, I was 18 forced to quit—at least 19 . When I reached into my purse to grab Eloise, (to refer to my e-mail for only the seventh time that morning), I found her 20 by fever. She was so hot that I dropped her immediately back into my bag. When I picked her up again, she was gone.
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