16/20. Floors two, three, and four of Sheldon and Leonard's apartment building are the same set just re-dressed for each scene. This can be seen in the fact that the scuff marks on the moulding are identical on each level as they walk up the stairs.
17/20. On five episodes or more of season six, Mayim Bialik's right hand was hidden in certain ways and camera shots to conceal the injury and glove with which she covered her hand because of an automobile accident that occurred in August of 2012.
18/20. Jim Parsons as Sheldon Cooper wears numerous shirts containing the number 73, this is also the year Jim was born in real life 1973, and Cooper repeatedly states that 73 is his favorite number.
19/20. Each of the male characters has a signature clothing article that is worn in virtually every episode: Sheldon: t-shirts worn over long-sleeve shirts; Leonard: hoodies worn over a T-shirt and under a jacket; Raj: sweater-vest worn over a shirt and usually under some type of outerwear; Howard: dickie worn under some type of outerwear. Howard usually has a pin on the left side of his dickie of the head of a space alien, and he wears large belt buckles.
20. Out of the main male cast-members, Howard is the only one who hasn't seen Penny naked in person; despite being the first to flirt with her.
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