成人大量血胸,出血量多
A.>200mlB.>500mlC.>1000mlD.>1500mlE.>2000ml
参考答案:C
解析: 成人大量血胸,出血量多在1000ml以上。
_______ in London for so many years, you must learned a lot about English culture. [ ]
A. to live
B. To have lived
C. Having lived
D. Living
一个信息表student,要求它由学号sno,姓名sname,性别sex,年龄age,4个属性组成。现在对这个现有的表增加一个入学时间cometime字段为日期型,下列语句正确的是______。
A.ALTER TABLE student ADD cometime DATE NOT NULL;
B.ALTER TABLE student ADD cometime DATE;
C.ALTER TABLE student DROP cometime DATE NOT NULL;
D.ALTER TABLE student MODIFY cometime DATE;