Переклад слова «flat» з англійської на українську мову

The water had a flat taste,like boiled water, but it was all right.
For several days we drifted down a warm flat sea.
Then the trees seemed to stop and I was walking on flat ground.
She broke off, and gazed thoughtfully at the flat roof of theshack.
The first one I saw made me lie flat in thecovert .