With all the wars, fighting and sadness in the world today, it's not only necessary, but also essential to have a good sense of humor just to help us get through each and every day of our lives. Putting a smile on someone's face when you know they are feeling down in the dumps ( 处于沮丧中), as the saying goes, makes me feel good and warms my heart.
How would you feel if you could not joke around with your wife, husband, child, co-worker neighbor, close friend, or even just someone that you are standing in line with at your comer store? I am always saying things that make others smile or laugh, even if I don't know the person I'm joking around with.My Grandma always found humor in everything she did, even if it was the hardest job anyone could imagine.This not only relieves stress in any situation, but also is common courtesy (礼貌) to speak to others that are around you.
I know of a few people that don’t have a funny bone in their bodies, as they say.Everyone around them could be rolling on the floor after hearing a great joke and they would sit there without the slightest smile on their face.They don't get the joke that makes others laugh. I am busting a gut while they just sit there, looking at me as if I were from outer space. How can people not get a really funny joke?
Laughing is essential to keep your stress levels under control. Without humor we would find ourselves with a lot of psychological problems, or on a lot of medications to keep us from going crazy. There is too much sadness in this present world. It drives people crazy. We all need to find a way to bypass the sadness and bring a little light into our lives. So, I believe our best medicine is to get together and tell some jokes and have some fun laughing together.
The phrase “busting a gut" in the third paragraph can be replaced by __________.

A．explaining carefully	B．speaking loud
C．keeping silent	D．laughing hard