At the beginning of this century, medical scientists made an interesting discovery: we are built not just of flesh(肌肉) and blood but also of time. They were   41   to show that we all have a ‘body clock’   42   us, which controls the   43   and fall of our body energies,   44   us different from one day to the next.
The   45   of a ‘body clock’ should not be too   46   since the lives of most living things are controlled   47   the 24-hour night-and-day cycle(循环). We feel   48   and fall asleep at night and become   49   and energetic during the day. If the 24-hour cycle is   50   most people experience unpleasant   51  . For example, people who are not   52   to working at night can find that   53   of sleep causes them to   54   badly at work.
  55   the daily cycle of sleeping and   56  , we also have other cycles which   57   longer than one day. Most of us would   58   that we feel good on some days and not so good on   59  ; sometimes our ideas seem to flow and at other times, they   60   do not exist.

A．anxious B．careful C．able D．proud

A．around B．inside C．between D．on

A．rise B．supply C．use D．movement

A．showing B．treating C．changing D．making

A．idea B．opinion C．story D．invention

A．difficult B．exciting C．interesting D．surprising

A．from B．over C．by D．during

A．dull B．dreamy C．tired D．peaceful

A．regular B．excited C．clear D．lively

A．shortened B．disturbed C．reset D．troubled

A．moments B．senses C．feelings D．effects

A．used B．allowed C．expected D．prevented

A．miss B．none C．need D．lack

A．show B．perform C．manage D．control

A．With B．Except C．As well as D．Rather than

A．waking B．moving C．living D．working

A．repeat B．remain C．happen D．last

A．believe B．agree C．realize D．allow

A．others B．the other C．all other D．other

A．only B．just C．still D．yet