Useful
It help to make the biodegradable waste jwill be rotten.Without it if biodegradable wastes is not rotten it wil occupied space until the space is full.
A bee is both harmful and useful
which stage of the mosquito is harmful
lion are useful and harmful
It is not harmful. Also it is not useful
flies are harmful because it can get your food dirty and it is like a mosquito
The vehicles are helpful because it help in transport the things the vehicles are harmful because it increase the pollution
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
Ozone at ground level is harmful. It is useful in stratosphere as it protects us from harmful UV rays.
eat bugs we don't want such as mosquito's
For humans, not particularly. But there are plenty of birds that eat them.