When you use a public telephone in a foreign country, be sure to read the directions carefully before dialing the number. In many foreign countries, as in China, a special number is assigned to each region of the country, which is called an "area code". If you know the area code and the phone number, it is usually easier and cheaper to dial the number yourself. In some foreign countries, such as in the UK and the USA, you can make reverse charge or collect calls with the help of an operator, and if the person you are calling accepts your call, he will pay for the call. Phone companies in both the UK and the USA also offer a credit card service, commonly called a phone card, to their customers. You get a card with an account number and a PIN (Personal Identity Number), which you can use for any phone. You pay for your calls after you have made them when the bill is sent to your home. 1. If you wish to make a call to China both easily and inexpensively, you have to know the (46) and the number. 2. That the person who (47) the call (48) is a reverse charge call. 3. A phone card is actually a (49) . 4. When you (50) of the calls you should pay for your calls.