执勤班长听到出动信号后，应带领（）迅速登山触动。
A、全队
B、全班
C、电话员
D、司机
参考答案：B
垂直于坝轴线方向的缝称为( )。
A．纵缝 B．斜缝C．错缝 D．横缝
An international bond investor has gathered the following information on a 10 - year, annualpay U. S. corporate bond: Currently trading at par value Annual coupon of 10% Estimated price if rates increase 50 basis points is 96.99% Estimated price is rates decrease 50 basis points is 103.14% The bond’s duration is closest to:（）
A. 6.58.
B. 0.62.
C. 6.15.
