下列物质中存在氧分子的是 A.水 B.双氧水 C.二氧化碳 D.液态氧
既能提供生命活动能量,又是组织细胞构成成分的是( )A.水、无机盐、蛋白质B.维生素、糖类、蛋白质C.糖类、蛋白质、脂肪D.维生素、水、
I went to India for a 2-week vacation to visit my relatives. We stopped on a red light, and as always, there were a lot of activities outside the cars near the 41 . People walked in, between
关于细胞结构与功能关系的描述中,错误的是( ) A.细胞膜上的糖蛋白与细胞的识别有关 B.细胞质基质不能为细胞代谢提供 ATP C.细胞核是细胞遗
请在下面的横线上紧接上文再写一个句子。要求:①另举一个事例;②句式与画横线的一句相同。 古往今来,彪炳史册的杰出人物,都曾做出过非
一个外来入侵物种,到达一个新的适宜环境后( ) A.将使原来生态系统的营养结构逐渐变得更加多样化 B.将使原来生态系统中能量流动的传递效率逐渐
下列说法正确的是 ( ) A、0是单项式 B、5的系数是5 C、2是5次单项式
Statistics show that men have _____ as women do for every mile they drive. A.serious accidents as twice many B.twice as many serious accidents C.twic