替喷
参考答案:
用密度较小的液体(一般为清水或清洁原油)逐步替出井内密度较大的压井液,使井底液柱压力小于地层压力,诱导油气从地层流入井内,再喷出地面的技术措施。
阅读判断正误,正确(T),错误(F)。
Jim is from England. He isn’t from the USA. He speaks English. His father is working in Beijing. So he
is studying in a middle school in Beijing. He has classes on weekdays. On Sundays, he often plays games with his Chinese friends. He likes China very much. He can speak a little Chinese now.
( ) 1. Jim comes from the USA.
( ) 2. He has no classes on Sundays.
( ) 3. He can’t speak Chinese.
( ) 4. His father is working in Beijing.
口腔颌面颈部的静脉()
A.分为浅静脉和深静脉两类
B.浅静脉接受浅层组织的血液,汇入深静脉
C.静脉血主要通过颈内静脉和颈外静脉向心脏回流
D.静脉的行径、分布大多与动脉一致
E.面部静脉较少,变异相对较少