Your answer is
One of the most effective methods that can be used by researchers to avoid sampling bias is simple random sampling, in which samples are chosen strictly by chance. This provides equal odds for every member of the population to be chosen as a participant in the study at hand.
I believe it's the first one.
There are few donor lungs available.<span>In 2010, about 1,800 lung transplants were performed in the United States.
Brainliest please?</span>
Tooth length is influenced by natural selection
when you have healthy teeth If you lose one
tooth chances are your other tooth will be
crooked until that tooth grows back in, Your
teeth all help each other keep each other strait.
But if you are not taking care of your teeth than
your teeth will not be strong enough to grow
longer or any bigger.