下列关于物质的物理性质及其应用的说法，正确的是[ ]

A．体温计中的水银，主要是应用其密度大

B．用橡胶做汽车的轮胎，主要是应用其硬度大

C．蹦床上的弹簧，主要是应用其弹性好

D．用铝做奥运火炬外壳，主要是应用其导电性好

In the early 1970’s, Citibank of New York City became one of the first financial institutions to install ATM’s on a large scale. Since then, the (1) of automated teller machines has increased dramatically. At the time, the bank hoped (2) their operating costs by replacing human tellers with machines. Little did they (3) that the cash machines would become so successful. However, as more banks added (4) automated service through ATM’s, the machines mushroomed all over the world.
To use an ATM, all you need is a (5) issued by your bank. Your bank may also (6) through a credit card, such as MasterCard or Visa. To begin a (7) , you need to insert the card into an ATM and punch in a personal identification number on the (8) . The personal ID number may consist of (9) and can prevent anyone from using the card.
The ATM next flashes instructions on its (10) for carrying out transaction. To get cash, for example, you are instructed to (11) that indicate whether the money should be withdrawn from a checking or a savings account and the (12) . This request is then displayed on the screen. After you press a button to (13) that the information is correct, the ATM goes to (14) .
How safe, you may ask, is banking by ATM The (15) is meant to prevent anyone, no matter who you are, from using a cash card (16) . If you enter the wrong ID number for a card, a message on the screen will (17) . If you fail to produce the correct number for three times, most machines will (18) .As another precaution against (19) , the bank generally limits the amount that may be withdrawn by cash card (20) , say, to $ 200.