Fe3+、SO42-、Al3+和X四种离子以物质的量之比2:4:1:1大量共存于同一溶液中,则X可能是[ ]
A.Na+
B.OH-
C.CO32-
D.Cl-
答案:D
I thought she was famous, but none of my friends have ______heard of her.
A.even
B.ever
C.just
D.never
妊娠合并心脏病中常见的类型
A.先天性心脏病
B.风湿性心脏病
C.妊高征心脏病
D.贫血性心脏病
E.高血压心脏病