对焊接头作拉伸试验时，三个试件的抗拉强度均不得低于该级别钢筋的规定抗拉强度值。
参考答案：对
一块面积为70亩的棉田，经测产亩铃数为11万个，该棉花品种的平均铃重为5克，平均衣分为40%，测产系数为95%，该棉田的皮棉总产是()吨。
Which of the following is the most widely accepted theory about the beginning of drama().
A.Drama came from seasonal changes.
B.Drama originated from ritual.
C.Drama evolved from stories.
D.Drama came from natural forces.
