Both. Whale blubber and oil can make useful objects. Whales are also vicious creatures. 40% of humans are killed by whales a year.
Blue whales are not at all harmful.
lion are useful and harmful
It is not harmful. Also it is not useful
The changes talking place in our surroundings and which are useful to us are called Useful changes. The changes which are not useful but harmful are called Harmful changes
useful
i think its both harmful and useful
it is useful
Ozone at ground level is harmful. It is useful in stratosphere as it protects us from harmful UV rays.
Helpful.
A carbohydrate can be useful or harmful depending on the type that is eaten. Good carbohydrates have fiber in them.
changes both harmful and useful
It is useful because we can breathe it.