Q: Does the word "do" mean the same thing in "Do research." and "This car does 150 miles per hour."?

A: different meanings

Q: Does the word "grain" mean the same thing in "Sand of a fine grain." and "A stone of coarse grain."?

A: the same meaning

Q: Does the word "chain" mean the same thing in "The third link of the silver chain needs to be resoldered." and "This led to an unfortunate chain of events."?

A: the same meaning

Q: Does the word "foot" mean the same thing in "The foot of the page." and "The foot of the list."?

A:
the same meaning