As viruses cannot reproduce by themselves, they depend on the host cells that they infect to reproduce
I believe it’s true, since Competition will occur between organisms in an ecosystem when both try to use the same resource and the resource is in limited supply. Animals compete for food, water and space to live. Plants compete for light, water, minerals and root space.
The pH will decrease because lemon juice is very acidic meaning it would bring the pH level down to a more acidic value.