题目

如图示DNA分子的片段，下列相关叙述正确的是（ ）A．④表示构成DNA分子的基本单位，⑦构成DNA分子的基本骨架B．DNA分子的多样性和特异性主要决定于④的种类和数目C．解旋酶作用于图中的⑤，限制性内切酶在①②之间断开DNAD．若整个DNA中T有M个，占碱基总数的a/b，则C的数目为M（b/2a﹣1）个 答案：DApple’s so-called iPhone 4 “Death Grip” ----where holding the phone in the left hand weakens the signal ---- may rank among the top marketing failures of the 2010s.Frustrated iPhone 4 owners don’t need to wait around for Apple to handle the problem. They can solve the calling problems on their own. I’ve got five guaranteed solutions, but you probably won’t like them.1.________________. In most US states, purchasers can return phones within 14 days - 30 days in states like California. It’s the “buyer’s regret” period, and for some people who can’t make clear calls there surely is some kind of regret. Apple’s newest handset may be the most fashionable phone on the planet, but it is by no means the only choice. Yes, you can use another smart phone and find happiness.2.________________. OK, so this might seem like an extreme choice, but, hey, aren’t all those phone calls annoying? I’ve dramatically reduced the number of phone calls and must say it feels good to be free of them. The iPhone has a touchscreen for a reason. Use it. But, please, don’t text and drive.3.________________. If you must make phone calls, change your location. Repeatedly test for the Death Grip, but don’t let the sellers know the real reason for moving. Surely they’ll think that anyone willing to wait all night in a line to buy a cell phone is some one who is easily tricked or taken in. Don’t let your iPhone 4 enthusiasm drive up the seller’s counter offer.4.________________. Hey, why should Apple be the only one who makes money? The iPhone 4 eBay auctions（拍卖）are crazy. There are “buy it now” prices of $1,000 and auctions with bids（出价）starting above $800. While writing this post, I watched one auction count down 7 minutes to zero, where in the final seconds the winning bid was $1,300 for the 32GB black model, unopened.5._______________. It’s surprising how effectively some people can just ignore problems like they don’t exist. No matter what the situation, they ignore it. “Hey, Johnny, don’t you know Toyota recalled（召回） a bazillion cars for accelerator pedal defects?” You know his answer: “Toyota is the best company on the planet. There is no problem with my car.” I’ve seen this kind of denial behavior among some Mac enthusiasts, too. About Death Grip, Apple CEO Steve Jobs is on record firmly stating: “Just avoid holding it in that way.” Apple claims the problem really isn’t iPhone 4 but you. Hey, you can choose to believe that. Denial will fix your problem, because you’ll never admit to having one.A. Live in denialB. Sell your iPhoneC. Stop making phone callsD. Purchase a car rather than an iPhoneE. Move to a location with strong carrier signalF. Return the phone and get one from a different manufacturer（制造商）