She was surprised __________ me last night. [ ]
A. to see
B. see
C. saw
答案:A
下列各组物质能在pH=0的溶液中大量共存,且形成无色溶液的是( )
A.NaClBaCl2Na2SO4
B.CuSO4KNO3NaCl
C.Na2SO4Na2CO3NaNO3
D.Na2SO4NaClHNO3
非任意抽样常见的形式有随意抽样、判断抽样和()。
A.单纯抽样
B.定额抽样
C.分层抽样
D.整体抽样