题目内容：
根据下列文章,请回答题。A Special ClockEvery Living thing has what scientists call A biologiCal clock that controls behavior．The biologiCal clock___________(1)plants when to form flowers and when the flowers should open．It tells insects when to __________ (2)the protective cocoon(防护卵袋)and．fly away，and it tells animals and．human beings when to eat sleep and wake．Events outside the plant and．animal___________ (3) the actions of some biologiCal clocks．Scientists recently found，for example that A tiny animal changes the color of its fur because of the___________l4)of hours of daylight．In the short__________ (5)of winter, its fur becomes white。The’ fur becomes gray brown in__________(6)in the longer hours of daylight in summer．
Inner signals control other_______ (7)clocks．German scientists found．that some kind．of internal clock seems to order birds to begin their long migration_______ (8)twiCe each year．Birds _______(9) from flying become restless when it is time for the trip，___________(1O)they become calm again when the time of the flight has ended．
Scientists say they are beginning to Learn whiCh _______ (11)of the brain contain biologiCal clocks．An AmeriCan researcher, Martin Moorhead．said．A small group of cells near the front of the brain_______ (12)to control the timing of some of our actions．These_______ (13)tell A person when to wake，when to_______ (14)and．whel7ito seek food．Scientists say there probably are other biologiCal clock cells that_______ (15)other body activities． A．says
B．asks
C．tells
D．talks
参考答案：
答案解析：