2.  1.Books  2.CD-ROMs  3.Internet

3. BooksCD-ROMSInternet Advantages  Familiarity  Ownership  Fast retrieval  Lots of information  Light-weight  Small size  Some contain pronunciation files  Some contain English learning materials  Some contain lots of pictures  Free  Wild-card searching Disadvantages  Large size  Slow retrieval  Computer needed  Slower retrieval process if users are computer dummies  Some are not well- designed  Computer needed  Internet connection needed  Slow internet speed  Free ones often have advertising

4.  1. Books  Advantages:  Familiarity - you have very probably used a book dictionary before.  Ownership - you've probably got one already, so you don't need to buy one.  Disadvantages:  Size - many dictionaries are large and heavy. Small (pocket-sized) dictionaries have much less information and can be hard to read.  Speed - finding a word can be a slow process.

5.  2. CD-ROMs  You can buy dictionaries on CD-ROM.  Advantages:  Finding a word is faster  CD-ROMs can contain a lot of information  They are light-weight  They are small  Some contain sound files for pronunciation (e.g. The Longman Interactive CD-ROM Dictionary)The Longman Interactive CD-ROM Dictionary  Some contain English language learning materials (e.g. The Longman Interactive CD-ROM Dictionary.The Longman Interactive CD-ROM Dictionary  Some contain pictures (e.g. The Longman Interactive CD-ROM Dictionary.The Longman Interactive CD-ROM Dictionary  Disadvantages:  You need a computer  It takes longer to start your computer, start the dictionary program and look up the word than it does to use a paper dictionary. If you are already using the computer however, this is not really a problem  Some CD ROMs are not well-designed as they seem not to use the abilities of computers (e.g. hyperlinking) very well  Due to the above disadvantages you should test the CD before you buy it, though not all shops will allow this.

6.  3. Internet  You can find some dictionaries on the Internet.  Advantages:  They are free.  Wild cards - you can type ? if you don't know a letter, or * for a group of letters you don't know; e.g. b?t will find bat, bet, bit, & but. b*t finds babysit, backseat, bait, ballet etc.  Disadvantages:  You need a computer  You need to be connected to the Internet  The Internet might be very slow  Some have distracting advertising

7.  1. General Dictionaries  These are normal dictionaries that give you information about the most common words in English. However, new words are often not included in these dictionaries until they become very common. Therefore you should look for new fashionable words and new technical words (especially computer terms) in a dictionary of slang or informal expressions or in a technical dictionary.

8.  2. Specialized Dictionaries  These are dictionaries :  Useful for special groups of people. E.g.: Advanced Learner's dictionaries, college students, children, etc.  Useful for special fields or professions (technical dictionaries). E.g.: medical, chemical, physical, literary, linguistic, computer dictionaries, etc.  Concentrating on one part of language. E.g.: dictionaries of idioms, collocations, phrasal verbs, abbreviations, etc.collocations  Translating between different varieties of a single language. E.g.: British-American dictionaries.

9.  Having a special organization. E.g.: thesauruses, which are dictionaries that list words with similar meanings together. This is useful for writing, where it is sometimes bad style to use the same word many times. However, you will need to use a general dictionary to discover the differences between the similar words. Some word-processing programs have a thesaurus in the Tools menu. Also, glossaries which are alphabetical lists of defined terms in a specialized field usually come at the end of certain books.

10.  1. monolingual dictionaries: all entries come in one language.  2. bilingual dictionaries: each entry has translations of words in another language.  3. multilingual dictionaries: each entry has translations of words in two or more languages.