A:①②
B:②④
C:③④
D:①④
⑴Can we look at the blue jeans?____ A. It's a shirt.
⑵What's this?____ B. They're shorts.
⑶What colour is it?____ C. Here you are.
⑷What are they?____ D. It's yellow.
如图,⊙O的半径为2,点O到直线l的距离为3,点P是直线l上的一个动点,PQ切⊙O于点Q,则PQ的最小值为( )