At the beginning of this century, medica
问题：
At the beginning of this century, medical scientists made an interesting discovery; we are built not just of flesh and blood but also of time. They were 36 to show that we all have “a body clock” 37 us, which controls the 38 and fall of our body energies, 39 us different from one day one to the next.
The 40 of “a body clock” should not be too 41 since the lives of most living things are controlled 42 the 24 hour night-and-day cycle. We feel 43 and fall asleep at night and become 44 and energetic during the day. If the 24 hour-cycle is 45 , most people experience unpleasant 46 . For example, people who are not 47 to working at night can find that 48 of sleep causes them to 49 badly at work.
50 the daily cycle of sleeping and 51 , we also have other cycles which 52 longer than one day. Most of us would 53 that we feel good on some days and not so good on 54 ; sometimes our ideas seem to flow and at other times, they 55 do not exist.
36．A．anxious B．able C．careful D．proud
37．A．inside B．around C．between D．on
38．A．movement B．supply C．use D．rise
39．A．showing B．treating C．making D．changing
40．A．invention B．opinion C．story D．idea
41．A．difficult B．exciting C．surprising D．interesting
42．A．from B．by C．over D．during
43．A．dull B．tired C．dreamy D．peaceful
44．A．regular B．excited C．lively D．clear
45．A．disturbed B．shortened C．reset D．troubled
46．A．moments B．feelings C．senses D．effects
47．A．prevented B．allowed C．expected D．used
48．A．miss B．none C．lack D．need
49．A．perform B．show C．manage D．control
50．A．With B．As well as C．Except D．Rather than
51．A．working B．moving C．living D．waking
52．A．repeat B．remain C．last D．happen
53．A．agree B．believe C．realize D．allow
54．A．other B．the other C．all other D．others
55．A．just B．only C．still D．yet