3. Which
on causes by loudspeaker?
4. Who is called true friend?
5. What can protect our Earth?
Answers
1=Noise is unwanted sound. Noise can be produced by many sources - man's vocal cord, a running engine, a vibrating loudspeaker diaphragm, an operating machine tool, and so on. ... The higher the frequency, the more high-pitched a sound is perceived.
2=A true friend shows up. They don't care if it's inconvenient, or if it's uncomfortable, or maybe it's a little dangerous, but they will show up. Those are the friends with whom you have an unwritten permission that you can call them at 3am if you want, and they show up for you.
3=Ten Simple Things You Can Do to Help Protect the Earth
Reduce, reuse, and recycle. Cut down on what you throw away.
Volunteer. Volunteer for cleanups in your community.
Educate.
Conserve water.
Choose sustainable.
Shop wisely.
Use long-lasting light bulbs.
Plant a tree.
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