恶性肿瘤全身转移的治疗包括（）
A.化学治疗
B.手术治疗
C.免疫治疗
D.放射治疗
E.中医药治疗
参考答案：A, C, E
《室外排水设计规范》规定，污水管道( )在设计充满度下的最小设计流速为( )m/s。
A．0.4
B．0.6
C．0.8
D．0.2
An analyst does research about relationship between credit spreads and economic well being. In general, credit spreads on corporate bonds tend to:（）
A. tighten during both economic expansions and economic contractions.
B. widen during economic expansions and tighten during economic contractions.
C. tighten during economic expansions and widen during economic contractions.
