Answer:
The length of the rope must be an integral multiple of the wavelength of the wave.
Explanation:
in china, there is a family limit for only having 1 child
at 10 billion people on earth, we will most likely run out of food supply
Answer:
Dark matter does not affect our view, humans can see through them.
Explanation:
They do not affect our view because we can see right through the (weakly interacting) dark matter, as they do not interact or interfere with electromagnetic force.
Dark matter are often invisible substances and are difficult to spot because they don't absorb or reflect light.