要除去KCl中混有的少量K2CO3,选用的试剂是[ ]
A.H2SO4溶液
B.稀盐酸
C.K2SO4溶液
D.AgNO3溶液
答案:B
新航路开辟过程中,率先完成环球航行的是()
A.迪亚士
B.达•伽马
C.哥伦布
D.麦哲伦船队
They often chatted about the hard times______they spent together in the old days.
A.where
B.when
C.which
D.what