Misc: In 1644 Olaus---------- , first to accurately measured speed of light, born. ?

Questions

A _______ is the only standard international unit of measure still defined by a physical object, a bar composed of two elements?

A ________ can eat only when its head is upside down?

A __________ can learn to recognize itself in a mirror?

A __________________ measures blood pressure?

A 3 1/2' floppy disk measures ___ & 1/2 inches across.?