下列去括号结果正确的是( )
A:a2-(3a-b+2c)=a2-3a-b+2c
B:3a-4a-(2a-7)=3a-4a-2a+7
C:(2x-3y)-(y+4x)=2x-3y-y-4x
D:-(2x-y)+(x-1)=-2x-y+x-1
新疆维吾尔自治区发展成就令人瞩目,近3年来GDP以千亿元速度递增,这得益于新疆丰富的自然资源的硬环境,更得益于我国民族区域自治制度、宗教信仰自由制度和新疆各族人民的艰苦奋斗、勇于拼搏的软环境。下列关于新疆发展的软环境的认识正确的有( )
Dear Jenny,
Now we are in the hospital of our city . My mother and I have a bad cold . We sees many children here . Some people have a cold. Some people have a headache. Some people have a fever. They a re waiting outside the doctor's room .Now it's our turn.
Yours,
Jack
如果 ,那么(-x)·y= ____ 。