Name a such thing that occurs twice in a day, once in a month and never in a year​

How can i prepare for iit ? ? subjects / chapters should i focus ? is non schooling is good for iit or not ? how much hours should i study during preparation ? expect answers from seniors

Explain menstrual dysfunction inbreif​

Type of organisation is suitable when the volume of business is large and huge capital investment is required. give any two advantages of such an organisation.