化简:a•a5+(-a)3•a3-(2a2)2•a2.
原式=a6-a6-4a6
=-4a6.
On hearing the news, she rushed out without hesitation, her handbag on the sofa and in the distance.
A.left; lied; disappeared
B.leaving; lying; disappeared
C.leaving; laying; disappeared
D.left; lying; disappearing
不符合Crohn病的描述是()
A.只累及回肠
B.呈节段性分布
C.常呈慢性经过
D.肠黏膜呈鹅卵石状外观
E.形成裂隙及匐行性溃疡