下列几组数中,为勾股数的是( )
A:35,45,1
B:3,4,6
C:5,12,13
D:0.9,1.2,1.5
①∠PCB=15°;
②AD∥BC;
③直线PC与AB垂直;
④四边形ABCD是轴对称图形.
其中正确的有( )
—Have you found the book ________ you lost yesterday? —Yes. I left it in the library.