苏子降气汤与定喘汤组成中均含有的药物是（）
A.半夏、甘草
B.苏子、杏仁
C.黄芩、桂枝
D.苏子、甘草
E.细辛、杏仁
参考答案：D
以下对双端面机械密封特点描述错误的为（）。
A.双端面机械密封分为平衡式和非平衡式两种
B.双端面机械密封有两对摩擦副
C.减少了泄漏量且密封面受力较为合理
D.双端面之间的空腔不可引入封液
Which of the following statements is TRUE（）
A. When a rating agency downgrades a security, the bond’s price usually falls.
B. Technical default usually refers to the issuer’s failure to make interest or principal payments as scheduled in the indenture.
C. Default risk is important because if a bond issuer defaults, the bondholder likely loses his entire investment.
