Use Present Perfect or Present Perfect Continuous:
1. Mary says she (forget) to buy some meat for dinner and asks me to do it, but I can’t. I am doing my homework, I (to do) it for two hours already and I (not, finish) all the exercises yet.
2. How long you (know) Mrs. Hurrison? – I (know) her for ages but I (not, see) her lately.
3. We (not, meet) the Johns for a long time. Is everything all right with them? - Yes, it is. I just (to speak) Mr. John on the phone.
4. Mark (learn) to drive a car for half a year already. But I don’t think he (become) a real driver.
5. Helen (dream) about going to Spain since last summer. I think she already (book) plane tickets for her trip.
6. I am afraid of Moscow roads. I always (be) afraid of them.

In greece and rome the earliest books were written on tablets of wood or pieces of bark covered with wax, and writing was possible upon them with a small stick called “stylus". in assyria and babylonia clay tablets were used for writing and the words were drawn with a piece of wood. after baking, the tablets were kept on shelves. they were long-lasting and some of them survived until the present day. the earliest books of the ancient world were written on papyrus and skins of young animals. these books took the form of a long strip, roiled from one cylinder to another. though paper has been known in china since the first century, the secret of papermaking came to europe much later. books were popular in ancient rome: there were many booksellers and the first public library was founded there about 39 b.c.1 only the rich could buy books or make their slaves copy books from important libraries. by the time, of the middle ages all books were handwritten, beautifully decorated, but they were often chained to the shelves. but only few people could read them. first printing was invented in china and by the end of the 15th century there were more than 200 presses in europe . the early printers were not only craftsmen but also editors, publishers and booksellers. the first printing, press in england was set up by william caxton at westminster in 1476. and the first printing press in russia — by ivan fedorov in moscow in 1564. early libraries were used only by scientists but latery they were used by the public. in the 19th century a proper system of public libraries appeared. now most countries have their own national libraries. many old university libraries have rich collections of books: oxford and cambridge in england, harvard and yale in the united states. among the great libraries of the world we can name the british museum library (the british library) in london, the library of congress in the united states, it’s the world’s largest library, bibliotheque nationale in france , the beijing library in china, the state public library in moscow. modern libraries do their best to help people get information as quickly as possible. they use computers and electronic catalogues.probably the most difficult problem for any library is to keep their books, journals and films.