В следующих предложениях выделена грамматическая основа. Определите, чем выражено подлежащее в ней. Переведите предложения на русский язык.

1. Water is necessary for all life on Earth.
2. Each group of nutrients has its particular function.
3. Next morning I felt hungry.
4. Appetite comes with eating.
5. The waiter brought a tray with tea, toast, butter and marmalade.
6. They speak four languages in Switzerland.