birdwatcher

If a girl sleeps with you in the same bed, does it mean that she wants to have sex?

REUTERS -- Researchers said on Friday long-term exposure to cosmic rays that permeate space may cause dementia-like cognitive impairments in astronauts during any future round-trip Mars journey, expected to take at least 2-1/2 years.
Думаю, заметно не будет.
P.S. Изучающим английский язык: что в этом предложении означают слова "on Friday"?