例句與造句

1. Then either some more complicated mirrors to get to a second mercury tank with 3kHz ripples-or ( more conveniently ) a 3000 revolutions per second spinning 10-sided mirror ( which would still have to be insanely carefully machined and mounted to avoid it destroying itself . . . but not impossibly so . 3000 revs per second is 180, 000 rpm-which is only 20 times faster than ( say ) a car engine spins . . . it's tough but just barely possible.
2. It's difficult to find mercury tank in a sentence. 用mercury tank造句挺難的