对每种型式、级别、规格、材料、工艺的钢筋机械连接接头，型式检验试件不应少于（）个。
A.6
B.3
C.12
D.9
参考答案：D
在农田生态系统中，生产者是指
A．农民
B．农作物
C．耕地
D．耕牛
— Could you tell me ______?
— I live in Liaocheng.[ ]
A: where you lived
B: where were you born
C: where you live
D: where you were born
