At 3 weeks, you can begin to offer toys to a newborn Yorkie puppies. At this time milk teeth can begin to erupt and puppies may enjoy having something to gnaw at. The 1st deworming may be done. Make sure that your dog's veterinarian approves. This will depend on the weight of the puppy and the pup's health.
One megahertz (abbreviated: MHz) is equal to 1,000 kilohertz, or 1,000,000 hertz. It can also be described as one million cycles per second. Megahertz is used to measure wave frequencies, as well as the speed of microprocessors. Radio waves, which are used for both radio and TV broadcasts, are typically measured in megahertz.
A hertz is a measure of frequency. Can also be referred to as cycles per second. 1 to 99 written as 1Hz. 2Hz etc. One mega-hertz = 100 hertz. (100 to 999) Written as 1Mhz, 2Mhz etc. A thousand up is called kilo-hertz written as 1Khz or just 1K, 2K etc. For more detail check the link to Wikipedia.