【判断题】在房室交界处传导速度缓慢,需时较长,称为房室延搁。
【单选题】平衡运输模型的约束方程的特点包括
B.
运输问题约束方程左边的每一列中恰有两个系数是1,其他都是0。
C.
有m+n-1个独立约束条件,该问题的基变量有m+n-1个。
【多选题】2What is the difference between D/P and D/A?
A.
D/P is much safer for the seller than D/A
B.
D/P after sight and D/A both adopt the draft.
C.
D/P belongs to collection but D/A can be remittance.
D.
D/P can be sight payment while D/A is only time payment.
【判断题】兴奋由窦房结传至心室时,在房室交界处传导速度缓慢,需时较长,称为房室延搁。
【单选题】演讲结尾时,一般可以()来鼓励听众、呼吁他们采取行动。