研究各国经济关系的主要指标是( )
A.国际市场价格
B.世界市场行情
C.对外贸易
D.旧际收支
参考答案:C
_______ any reply, he had to send a second request. [ ]
A. Not to receive
B. Having not received
C. Not receiving
D. Not having received
现有四组物质的溶液,仅用酚酞溶液及同组物质之间相互反应就能鉴别出来的是( )
A.NaOH、Ba(OH)2、HCl
B.NaOH、HCl、NaCl
C.NaOH、HCl、HNO3
D.H2SO4、NaCl、Na2SO4