听力题 In phone booths in the U. S. there are usually directions for using the telephone. All phone numbers have seven digits, though letters and numbers are sometimes used in combination. There may be phone books-or directories -under the telephones. There are two main kinds of long distance calls: direct dial and operator-assisted. You can direct dial calls in most parts of the U. S. Look in the white pages directory for long distance rates or for more information on making long distance calls. Or you can call the operator for help. If you need a phone number that''s not in your phone book, call Directory Assistance. To make a long distance call, you''ll need to know the three digit area code. Dial 1 plus the area code plus the number, and an operator or a computer voice will tell you how much money to deposit. On operator assisted calls, the operator will ask you to deposit more money before your time is up. On direct dial calls you''ll be cut off at the end of the time you paid for unless you put more money in the slot.