How do astronomers test the existence of black holes? do you think you could give some suggestions how to observe what is not visible? if so, what suggestions it would be?

Ateam of researchers calculates that a glacier will melt completely away in the next 100 years. which land structure will most likely be left behind after the glacier melts?

The great scientist alfred wegener proposed that continents have moved, while other scientists such as t.c.chamberlin argued against wegener. wegener's ideas eventually won, and are now widely accepted, because: a) wegener's ideas were more beautiful, and so were favored by the intellectual elite.b) wegener's ideas did a better job of predicting the results of new observations and experiments.c) wegener's ideas appealed to dead white european males, whereas chamberlin's didn't.d) wegener's ideas appalled dead white european males, and we all know that in this politically correct era,dead white european males cannot get a fair shake.e) wegener won the nobel prize.

Which of these fragmental sedimentary rocks would most likely form farthest from the land?