The term that best completes the given statement above is the word ATTENUATED. A method of producing an attenuated vaccine is through genetic manipulation of a microbe to remove one or more virulence factors. The purpose of creating attenuated vaccines is to reduce the effect of a microorganism to the body. Once the body is exposed to the said disease, it will not experience a dreadful effect done by the microorganism.
Today, one second is defined as “9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom”. That's a mouthful.