测压管进水管段外部包扎防止周围土体颗粒进入的无纺土工织物，透水段与孔壁之间用（）填满。
A．粘性土
B．粘土泥球
C．砂性土
D．反滤料
参考答案：D
-Have you had __________ breakfast yet?
-No, not yet.[ ]
A. /
B. a
C. the
D. an
