to solve a complex problem or mystery
решить сложную проблему или загадку (reshit slozhnuyu problemu ili zagadku)
"It took hours, but we finally cracked the code of the system error."
"Это заняло несколько часов, но мы наконец разгадали код системной ошибки." (eto zanyalo neskolko chasov no my nakonec razgadali kod sistemnoy oshibki)
to become more ill
to plan a new direction or strategy
don't make plans for something that might not happen
To tell someone important or bad news.
to criticize someone angrily
to appear happy and cheerful