Personalized Pop Quiz Sister Best Teacher Youth T-Shirt. Forget the chalkboard. Funny teacher appreciation Youth T-Shirt - Pacific Blue with apple and pencil will express love and support for your favorite educator teacher says POP QUIZ WHO'S THE BEST TEACHER? MY SISTER. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.