a small visible part of a much larger problem
небольшая видимая часть гораздо более крупной проблемы (nebolshaya vidimaya chast' gorazdo bolee krupnoy problemy)
"The few complaints we received are just the tip of the iceberg."
"Немного жалоб, которые мы получили, это всего лишь верхушка айсберга." (Nemnogo zhalob, kotorye my poluchili, eto vsego lish' verkhushka ayzberga.)
to face a difficult situation bravely
to try to achieve something impossible
to successfully enter a new market or industry
to take a risk by supporting something or someone
outside the planned or expected area of focus
to start something; to begin working or functioning