2013年4月20日四川雅安发生7.0级地震,灾区饮用水与食品安全备受关注. (1)水中难闻的异味,可添加活性炭除去,这是利用了活性炭的_________性. (2
—Do you think that man will come to your help? —I really don’t know a person like him can help me with. A.how B.what
I never doubt ______ his advice is of great ______ to me.A.that; valuableB.if; valueC.whether; valuableD.that; value
某同学在刷牙时经常发现牙龈出血,你建议该同学在饮食上应多吃 A.青菜 B.肥肉 C.动物的肝脏 D.牛奶
— It is around 100 years, known to us all, ______ the first modern Olympic Games was held. — It really is. But were _____ ? A. that; was that B. since; was it C. after; is that
)回收的废旧锌锰于电池经过处理后得到锰粉(含MnO2、Mn(OH)2、Fe、乙炔和黑炭等),由锰粉制取MnO2的步骤如下图所示。根据上图所示步骤并参考表格数据,
一种称为“摇头丸”的毒品,已从国外流入我国,司法机关予以坚决查缉打击。已知该毒品中含氮10.37%,其结构可能是( )
在减数第一次分裂间期,因某些原因使果蝇Ⅱ号染色体上的DNA分子缺失了一个基因,这种变异属于( ) A. 染色体变异 B