病毒生活的环境必须是 A.水中B.空气中C.土壤中D.活着的细胞中
Last night I had a terrible cold and ached all ___________. A. the way B. over C. at once D. the worst
“人心齐,泰山移”。具备团队精神是现代人才必备素质,因为 ( )A.成功只是个人努力的结果B.团结的集体才有凝聚力和战斗力C.个人
So sudden ________that the enemy had no time to escape. A. did the attack B. the attack did C. was the attack D. the attack was
口腔上皮细胞和洋葱鳞片叶表皮细胞相比,口腔上皮细胞不具有的结构是( ) A.细胞膜 B.细胞壁
(09广州市一模)(现代生物科技专题,10分)阅读下列材料并回答有关问题:ω-3脂肪酸是深海“鱼油”的主要成分,它对风湿性关节炎以及糖尿病等有
化简:=_______________________。