函数y=﹣2exsinx(1≠a>0)的导数是[ ]
A.﹣2excosx
B.﹣2ex(sinx﹣cosx)
C.2exsinx
D.﹣2ex(sinx+cosx)
答案:D
—Thank you, Thomas. —________.
A.I’m happy.
B.That sounds great.
C.You’re welcome
D.Have a good day.
稻禾的仇敌是谁?()
A.蝗虫
B.小蛾
C.毛毛虫