2002年4月,以杭州华大基因研究中心和浙江大学生物信息学研究中心为主体的中国科学家成功破译了水稻基因组信息。下列有关水稻遗传物质的叙述错误的是 ( )A.水稻基因实质上是水稻DNA分子上起遗传作用的一些片段B.水稻抗病、抗倒伏、高产优质等一系列可遗传的性状均由基因决定C.水稻DNA分子是一种大分子化学物质D.水稻、人类等生物体内的基因、DNA、染色体不可能发生变化
Becky won't let Joe down if he ______ her a hand in tomorrow's competition.( )
A.givesB.giveC.gaveD.will give
Lucy,could you please help me_______ the map on the wall? We need it now.( )
A.put downB.put onC.put offD.put up
Is this photo taken in Tibet?
Yes,you can see beautiful snow mountains in the _______of the photo.( )
A.expressionB.background
C.introductionD.shape
What were Helen and Sally doing when it began to rain heavily?
Helen was sleeping _______Sally was reading a magazine.( )
A.whileB.untilC.beforeD.after
Mum,_____ I go out to watch a movie?
Yes,you can.But you must finish your homework first.( )
A.mustB.needC.willD.may