在正常小麦的体细胞核内含有碱基和核苷酸的种类分别是( ) A.4,4 B.4,8 C.5,8 D.
有一种含碘和氧两种元素的化合物,可称为碘酸碘,其中该化合物中的碘元素呈现两种不同价态+3价和+5价,根据你的现有化学知识水平和综合能力,请
如图,已知两点A(2,0), B(0,4),且,则点C的坐标是__________
下列词语中加点的字,读音全都不相同的一组是( ) A.惆怅 啁啾
下列各组物质的溶液混合后,不能发生反应的是( ) A.NaCl和H2SO4 B.NaOH和HCl C.Na2CO3和H2SO4 D.AgNO3和NaCl
__________the news,he said nothing and went away. A.After being told B.Although being told C.While being told D.Being told
—Excuse me, _____ is Zhongshan Park from here? —It’s about seven kilometers. A. how long B. how often C. how far D. how much