A:0.1 mol/L Na2CO3溶液:c(OH-)=c(HCO3-)+c(H+)+2c(H2CO3)
B:0.1 mol/L NH4Cl溶液:c(NH4+ )=c(Cl-)
C:向醋酸钠溶液中加入适量醋酸,得到的酸性混合溶液: c(Na+)>c(CH3COO-)>c(H+)>c(OH-)
D:向硝酸钠溶液中滴加稀盐酸得到的pH=5的混合溶液:c(Na+)>c(NO3-)
—Scientists all over the world are ______ new drugs to treat cancer.
—It will help many sick people.
回答下列有关实验仪器和实验操作的问题:
选出不同类别的单词。
(____)1. A. plate B. how C. cake
(____)2. A. some B. many C. how
(____)3. A. is B. one C. three
(____)4. A. one B. a C. an
(____)5. A. you B. they C. this
下列各句中,所引诗句不符合语境的一项是( )