Most babies are able to begin sitting up when they reach the age of 4 months. However, some of them might need more time and start sitting independently when they become 7 months old. Until this time, the baby would definitely have learned how to roll and would be able to hold his head up too.
UV radiation, in the form of lasers, lamps, or a combination of these devices and topical medications that increase UV sensitivity, are sometimes used to treat patients with certain diseases who have not responded to other methods of therapy.
The low risk posed by X-rays to a mother and her unborn baby means that ultrasound is used instead of X-rays for pre-natal checks. Other uses of X-rays Before the use of gamma rays [gamma ray: A type of ionising radiation that consists of a high-energy electromagnetic wave.] , a high-energy, concentrated dose of X-rays was used to treat some cancers.