Choose the correct answer:
STOPPING A JUMBO JET
In the early day of aviation, pilots had more important things to worry about than braking. Their main problem was getting into the air. (1)..... by using all available horsepower (2)..... they able to work up enough speed to take off. When they landed again, their machines had so little weight and momentum that they rolled to a halt on the grass only a few metres (3)....
Those days, (4)...., are long gone. As aircraft weights have risen, (5).... have landing speeds, which has meant that undercarriage brakes (6)..... had to become more effective. Today, airlines travelling at speeds of up to 250 kilometres per hous are (7).... brought down to taxiing speed in a (8)..... of seconds. A jumbo coming in to land can weigh more than 200 tons, so its wheels are (9).... with a complete set of disc brakes. (10).... it simply allowed to roll to a halt, it qould need a runway twice the normal length.
Airlines, therefore, have a second braking system which, (11).... a passenger, you cannot fail to hear during landing. Hardly have the tyres made (12)....with the ground (13)...... the engines start roaring again. This is the system known as reverse thrust (14)..... applied, the effect of which is to slow down the aircraft well before it (15)..... the end of the runway.
1. Even/ Only/ Not
2. were/ should/ could
3. when/ by/ after
4. despite/ however/ although
5. so/ and/ also
6. have/ would/ had
7. being/ about/ to
8. few/ matter/ lack
9. placed/ equipped/ found
10. Although/ Were/ If
11. like/ as/ because
12. touch/ contact/ communication
13. than/ that/ when
14. be/ being/ is
15. gets/ reaches/ arrives