铝、铁、铜是我们生活中常见的金属。
(1)铝制品具有很好的抗腐蚀性能，是因为铝在空气中其表面易形成致密的____________薄膜。
(2)图甲中发生反应后能生成______色固体，做该实验时，在集气瓶中预先加入少量水可以防止_____________________________。
(3)少伟同学从生活中发现，在潮湿的空气中铁比铜更容易锈蚀，由此他认为铁的金属活动性比铜_________（选填：“强”或“弱”)。他还想通过一个实验(如图乙)来进一步证明，并图乙中A为金属铁，你认为B是__________溶液。发生该反应的化学方程式是_______________________________。
(1)氧化铝(或三氧化二铝或Al2O3或氧化物)
(2)黑；集气瓶破裂
(3)强；CuSO4 (或CuCl2)(填名称也可)(合理即可)
Fe+CuSO4==Cu+FeSO4 (或Fe+CuCl2 ===Cu+FeCl2)(合理即可)
Passage Three
| Junk Hunting 淘旧货 Anyone who thinks exploration always involves long journeys should have his head examined.Or, better, he should put on his oldest clothes and go off in search of a junk shop. There are three kinds—one full of discarded books, one full of discarded Government equipment, and one full of discarded anything.A junk shop may have four walls and a roof,or it may be no more than a trestle-table in an open air market;but there is one infallible test:no genuine junk shopkeeper will ever pester you to make up your mind and buy something. And you are no true junk shopper if you march purposefully round the shop as if you knew exactly what you wanteD．You must browse, gently chewing the cud of your idle thoughts, and nibbling here and there as a sight or a touch of the goods that lie about you. Yet you must also possess a penetrating glance, darting your eyes about you to spot the treasures that may lurk beneath the rubbish. This is what makes junk shopping such a satisfying voyage of exploration. You never know what interesting and unexpected thing you may discover next. For in a true junk shop, not even the proprietor is always quite sure what his dusty stock conceals. There is always the chance that you may pick up a first edition, a pair of exotic ear-rings, a piece of early Wedgwood china, or a cine camera—and possess it for the price of fifty cigarettes. But this kind of treasure hunt is only a sideline to the true junk shopper. The real attraction lies in finding something that catches your own especial fancy, though everybody else may pass it by. An ancient tarnished clock, whose brass beneath your hands will shine anew; empty boxes that you can see transformed into the framework of a bookcase; an old bound volume of magazines of three-quarters of a century ago, which will shed strange sidelights on the ways our great-grandparents behaved and looked at life. When you begin junk shopping, half the attraction is that you go with absolutely no intention of buying anything. You spend your first couple of Saturday afternoons ambling around among dusty shelves, savouring a page or a chapter as you please, or fingering the piles of oddments that litter counters or tables. At first, be warned, don’t try to buy. You may, indeed you should, ask the price of this and that; but just to give you an idea of what the junk shopkeeper thinks you might be willing to pay him. Later, you will find yourself returning a second and third time to something that has caught your fancy. And when you can hold back no longer, bargaining begins in earnest. This is the other great attraction of the true junk shop. Not only may it hold every conceivable product from every imaginable country; it also transports you to the mediaeval market place or the oriental bazaar, where no price is fixed until buyer and seller have waged a friendly war together, and proved each other’s mettle. And this is where your old clothes become important: let no one take you for a rich connoisseur, or you will find yourself paying a rich man’s prices. And avoid at all costs the suspicion of an American accent, or in spite of the good nature of all good junk shopkeepers, you will be for it. |
The author suggests that the junk buyer’s main reason for bargaining is______.
A．to fix a price
B．that he hasn’t enough money
C．that it’s expected
D．to ask a price