Trees produce the oxygen that humans need to breathe
Google that man, you don't need to use brainly, look for synonyms of critical, but that info should be in the defenition.
For me:
So for us to be healthy and free from silent killers we must eat the right kind and amount of food specially fruits and green leafy vegetables.
I would say that learning another language is the most important for communication especially if one is in the country where the other language is spoken and is immersed in it then to be able to survive then one must learn the language and also the process of learning it requires reaching out to the local people and relying on their assistance which bonds one with the people of that country.
