A:伏尔加河
B:叶尼塞河
C:勒拿河
D:鄂毕河
在①Ca(HCO3)2;②Al2O3;③KAlO2;④C2H5OH;⑤⑥Al这六种物质中,既能与强酸溶液(如HCl),又能与强碱溶液(如NaOH)反应的有____ .
The young man sat down and watched his son a lovely cat.
如图,正方形ABCD内接于⊙O,E为DC的中点,直线BE交⊙O于点F,若⊙O的半径为2,则BF的长为____ .
loved, her, very, her, much, parents, (.) (连词成句)
____