【简答题】若x<0,y<0,且-x>-y,则x-y______0(填“<>=”)
【单选题】根据项目运作方式和还款来源不同,固定资产贷款可分为()
【单选题】命题“若x 2 +y 2 =0,则x、y全为0”的逆否命题是
【单选题】一女性患者,20岁,因发现盆腔肿块行剖腹探查术,术中取肿块组织送病理检查,报告为“卵巢无性细胞瘤”。该肿瘤属卵巢哪一类肿瘤
【单选题】命题“若x 2 +y 2 =0,则x,y全为0”的否命题是( )
C.
若x 2 +y 2 ≠0,则x,y至少有一个为0
【单选题】The machine hasn’t been in use for a long time. I wouder whether it is in good ______.
【单选题】“若x,y∈R且x 2 +y 2 =0,则x,y全为0”的否命题是( )
A.
若x,y∈R且x 2 +y 2 ≠0,则x,y全不为0
B.
若x,y∈R且x 2 +y 2 ≠0,则x,y不全为0
C.
若x,y∈R且x,y全为0,则x 2 +y 2 =0
D.
若x,y∈R且xy≠0,则x 2 +y 2 ≠0
【单选题】“若x,y∈R且x 2 +y 2 =0,则x,y全为0”的否命题是( )
A.
若x,y∈R且x 2 +y 2 ≠0,则x,y全不为0
B.
若x,y∈R且x 2 +y 2 ≠0,则x,y不全为0
C.
若x,y∈R且x,y全为0,则x 2 +y 2 =0
D.
若x,y∈R且x,y不全为0,则x 2 +y 2 ≠0
【单选题】The historical sciences have made us very conscious of our past. They have made us conscious of the world as a machine. The machine generates successive events out of foregoing ones. Some scholars ten...