1. The Big Bang clan gather around in "The Graduation Transmission"
Wolowitz questions his engineering abilities when he and Sheldon can't get a toy drone to fly. Meanwhile, a cancelled flight nearly prevents Leonard from giving the commencement address at his former high school, and Raj pits his parents against each other when his father cuts him off financially, on THE BIG BANG THEORY, Thursday, April 23 (8:00-8:31 PM, ET/PT), on the CBS Television Network. Pictured left to right: Simon Helberg, Kunal Nayyar, Melissa Rauch, Mayim Bialik, Jim Parsons, Kaley Cuoco-Sweeting and Johnny Galecki Photo: Michael Yarish/CBS ©2015 CBS Broadcasting, Inc. All Rights Reserved