不属于钻井工程实施过程三个阶段的是（）。
A、钻进阶段
B、钻前准备阶段
C、钻井阶段
D、完井阶段
参考答案：A
下列公共传输信道中属于上行传输信道的有（）。
A.BCH
B.RACH
C.FACH
D.CPCH
We _________ our breakfast when an old man came to the door.
A．just have had
B．have just had
C．just had
D．had just had
