如图,四边形ABCD∽四边形A1B1C1D1,AB=12,CD=15,A1B1=9,则边C1D1的长是( )
A:10
B:12
C:454
D:365
——Would you like to come to my house for dinner tonight?——I'd love to , _____ I have lots of work to do .
下列四幅图,表示了近视眼、远视眼成像以及矫正后的成像情况,其中表示近视眼成像情况和矫正办法的是( )
设x,y∈R,a>1,b>1,若ax=by=3,a+b=23,1x+1y的最大值为____
“α=π6+2kπk∈Z”是“cos2α=12”的( )