Use "main source of income" in a sentence

1. What is their main source of income?

2. Circa 85% of the land area is covered with forest, and the timber industry has historically been the main source of income.

3. Most farms (25,500 out of 39,120) are family-managed; beef and wool represent the main activities and main source of income for 65% of them, followed by vegetable farming at 12%, dairy farming at 11%, hogs at 2%, and poultry also at 2%.

4. At the same reform, the current municipality of Lesbos was created out of the 13 former municipalities on the island: Agia Paraskevi (Αγία Παρασκευή) Agiasos (Αγιάσος) Gera (Γέρα) Eresos-Antissa (Ερεσός-Άντισσα) Evergetoulas (Ευεργέτουλας) Kalloni (Καλλονή) Loutropoli Thermis (Λουτρόπολη Θερμής) Mantamados (Μανταμάδος) Mithymna (Μήθυμνα) Mytilene (Μυτιλήνη) Petra (Πέτρα) Plomari (Πλωμάρι) Polichnitos (Πολίχνιτος) The economy of Lesbos is essentially agricultural in nature, with olive oil being the main source of income.