Read the paragraph given and answer the following questions.
Oceans and continents are vital parts of the environment and affect most aspects of our lives, even if we do not notice it. We have mentioned that oceans send rain to the continents; this is part of the Earth’s water cycle, which you will further study in science.
Without oceans, for instance, there would be no rainfall! The Earth would be a desert. Moreover, more than half of the world’s oxygen is produced by the oceans’ flora, which is why they are called ‘the planet’s lung’s. The oceans, therefore, play a crucial role in regulating the climate and sustaining life on Earth.
Oceans have deeply impacted humanity in many other ways. From early times, people have used oceans and seas to migrate to other regions, to trade in all kinds of goods, to conduct military campaigns, and as a source of food through fishing. Oceans have also nourished the cultures of coastal people all over the worid. Almost all of them have tales and legends about the sea, sea gods and goddesses, sea monsters and treasures from the sea the oceans’ dangers but also their blessings.
(i) How do oceans contribute to the Earth’s water cycle, and what would happen to the Earth without oceans ?
(ii) What is the significance of the flora in the oceans concerning the Earth’s oxygen supply ?
(iii) How have oceans historically impacted human activities and civilisations ?