Read the text below and decide which answer (A, b, C or D) best fits each space. There is an example at the beginning (0).



WHY ARE THEY SO WEIRD?



When they finally (0) ___B___ at lunchtime on a Saturday and need a crane to get them up on schoolday mornings, teenagers are not just being lazy. Their biological clocks (1)
____
__A__
on a different time of adults, because the hormone melatonin, which (2)
____
__D__
sleepiness, starts to be secreted in the brain much later at night and (3)
____
__B__
later in the morning.

Researchers have found that student do worse in exams when they (4)
____
__A__
them in the morning compared with in the afternoon. 'Teenagers' body clocks can be delayed by between two and four hours, and they don't start to (5)
____
__D__
until at least 10 a.m.', says professor Russell Foster, a neuroscientist at Oxford university. 'The timetable is not very well thought (6)
____
__C__
. It is cruel to impose a cultural (7)
____
__B__
on teenagers that make them underachieve,' he adds. 'Most schools' regimes force teenagers to work at a time of day that is suboptimal, and many university students are (8)
____
__A__
to considerable dangers from sleep deprivation,' Prof. Foster says.

Teenager who hide in their rooms may be (9)
____
__B__
and just need to (10)
____
__D__
. Strauch, another neuroscientist, says, 'That doesn't mean we are not supposed to have them take out the rubbish and be part of the family. But it does teach us that there are enormous changes going on inside their brains.

'I think the most (11)
____
__B__
thing it teaches us is that they aren't finished yet. That helps us to be a little bit more patient. Teenagers may look grown up but they are not grown-ups. There is still a lot of development (12)
____
__D__
in their brains.'


0 A stand up B surface C raise D come up
1 A run B go C tick D perform
2 A advances B furthers C develops D promotes
3 A waits B lingers C persists D endures
4 A sit B fix C place D set
5 A act B behave C produce D function
6 A about B of C out D over
7 A plan B pattern C method D manner
8 A exposed B revealed C shown D presented
9 A over-excited B over-stimulated C over-aroused D over-animated
10 A break off B run out C make off D get away
11 A relieving B reassuring C supporting D calming
12 A emerging B coming to light C transpiring D taking place