toefl writing practice. today we'r going to talk about weather and orgination a controll by biological clock or by other external fact, resarch have condected and experament with flying crows,flying crows normaly have 24 hours cycle to discover weather ther are efacted by the biological clock or external fact, resarch planed this crows in darkness are surrounding for 7 days to see of the steel have 24 hours cycle regardless ther envorment,are those this crows verry active in the dark it turn out when the captain darkness samulating hight for long direction of time they only have 23 and half hour sycle wich means that they are sycle was 30 minute faster,then this flying scrows was place back to ther original envorment with sunlight,after bieng kept in dark for longtime and seen the light the score return to the original sycle,this demistreet a cash and wich orgination has controll by external fact not by the biological clock.