Module 4,Unit 2,Its a black dog.,Lets sing a song.,red,blue,black,green,yellow,dog,Its a dog.,black,Now,its a dog.,blue,cat,Its a cat.,red,Now,its a cat.,green,yellow,Its a cap.,cap,Now,its a cap.,red,Its a chair.,green,Its a chair.,yellow,Its a chair.,blue,Its a desk.,black,Its a desk.,red,颜色-记忆力大考验,