The horse swithed its tail to drive the flies away.
马甩动尾巴以驱赶苍蝇。
2
I swithed TV over from CCTV4 to CCTV9 to watch English programmes.
我将电视从中央4套换到中央九套看英语节目。
3
So I then swithed to computer science and found out there was a lot of mathematics that I didn't have that I should had if I was going to going to the computer science.