【简答题】紫外线照射能使DNA产生______,从而导致DNA复制产生错误;用紫外线诱变微生物应在______条件下培养,以防______现象的产生。
【单选题】Teens aren ’ t Getting Enough Sleep Most teens need about 8 to more than 9 hours of sleep each night . The right amount of sleep is essential ( necessary ) for anyone who wants to do well in test s or...
A.
. To explain the reasons why teens are lack of sleep .
B.
. To draw people ’ s attention to teens ’ sleeping problem .
C.
. To introduce that we have the problem of sleep shortage .
D.
. To give teens advice on possible ways of having better sleep .
【单选题】The way the pocket money is given influences how money is spent or saved.
【简答题】It is worrying that nowadays more and more agers have free access to the Internet. Ideas for reference: T he Internet is a virtual world of unpleasant stuff of all kinds . T eenagers are vulnerabl...
【判断题】五四运动,是一场以先进青年知识分子为先锋、广大人民群众参加的彻底反帝反封建的伟大爱国革命运动。
【单选题】¿En qué zona de España localizas Castilla?
【简答题】紫外线照射能使DNA产生( ),从而导致DNA复制产生错误,用紫外线诱变微生物应在红光条件下进行,以防止( )现象产生。