Misc: Who was elected US president four times?

Questions

where is arthur c. clarke presently residing (as of 1999)?

when was the constitution fully ratified?

what is a nautical knot (international)?

in what famous sci fi flick did an einsteinlike scientist say to a space alien 'sit down. i have several thousand questions i'd like to ask you?

how many 'joeys' can a female kangaroo have in her pouch at one time?