What do cells do before beginning mitosis?? (science btw)

Simple astronomical telescope the objective lens has a focal length of 75 cm and that of a piece of 5cm of the lenses are 18 cm apart when will be final image of a distant object before

Which barrier to economic development is shown in the following examples? i. the high rate of hiv infection in underdeveloped nations ii. the use of children as soldiers in uganda’s army in the early 2000s iii. low literacy rates in underdeveloped nations with limited exposure to adequate education a. foreign debt b. political instability c. widespread disease d. low levels of social welfare

Where did the solar system come from?