1 tina doesn't teach mathematics to young children. does tina teach <span>mathematics to young children.
2she didn't meet her friends yesterday evening. did she meet her friends yesterday evening.
3the birds will not eat the old bread left in the garden. will the birds eat the old bread left in the garden</span>
<span>1. to create
1. mammal
3. environment</span>
Я читаю книгу. I read book.
Я играю в игры. I play in games.
Я иду домой. I go to home.
6. are you watching
7. don't like
8. did you stay
9. did Susan enjoy
10. did
1) During this period the track structure has been substantially improved.
One of the greatest improvements was the elimination of rail joints. In
order to reduce the number of joints the rails are welded into
continuous lengths.These continuous or long welded rails have greater
strength and provide a smoother running of trains at far greater speeds.
2) Another improvement which has made it possible to increase speeds on
railways is the use of concrete sleepers. Thus in some countries ,
concrete sleepers have replaced wooden ones on heavily used main lines
because of their advantages.
Concrete sleepers have a longer life
and a far greater weight than those made of wood. The greater weight of
concrete sleepers provides the greater stability of track.
It is this factor which has greatly contributed to increased speeds.
Ответ взял прямо из текста. Насколько я помню, так надо делать в подобных заданиях.