What is the appearance of milky quartz caused by

Iknow the answer is a but i don't know why

The minerals found in bones are deposited by living cells called

While in europe, if you drive 125 km per day, how much money would you spend on gas in one week if gas costs 1.10 euros per liter and your car’s gas mileage is 32.0 mi/gal? assume that 1 euro=1.26 dollars