29. Three new factories__they year. A) built B) were built C) have been built D) were built 30. 10.000 cars__next yers A) will produce B) produced C) are produced D) will be produced 31. The television __by Bell. A) was invented B) is invented C) wasn't invented D) invented 32.__ they___ many cars last year? A) Have / made B) Did / make C) Will / make D) Been / made Nylon (33) in the early 1930s by an American chemist, Julian Hill. Other scientists (34)_ with his invention, and finally on 27 October, 1938 nylon (35)_ to the world. It was cheap and strong and immediately_(36)_ successful, especially in the making of women's this year. stockings. During the Second World War, the best present for many women was a pair of nylon stockings, but more importantly, nylon_(37)_to make parachutes and tires. Today, nylon_(38)__ in many things: carpets, ropes, seat belts,​