Because you will focus past ("overshoot") your specimen. (Like using a race car as a shopping cart: it's too fast, and you'll fly past the cereal and never even see it before you realize you need to stop.) Also: you risk crushing the slide and objective against each other (on older or cheaper scopes), and that would be a costly (and embarrassing) mistake.
They form an organ
Have a nice day
Answer:
Radio waves, microwaves, infrared and visible light can all be used for communication.
Answer:
carbon-to-carbon double bond
