（）是最好的试压介质，地面井控设备试压时，对高压气井最好用（）作为试压介质。
参考答案：水清水；氮气之类的惰性气体
1989年民主德国宣布开放东西柏林边界，民主德国边防兵把一个小孩抱到柏林墙上，让他看一眼西柏林市景，这反映了 [ ]
A．两德统一在望
B．两个德国出现
C．两极格局形成
D．美苏“冷战结束”
—________ many buildings in your new school?
—Yes, ________.[ ]
A. Is there, there is
B. Are there, there is
C. Is there, there are
D. Are there, there are
e is