A millilitre is a volume of 1 cm3. You can measure this quantity of volume by a measuring tube, burette or pipet tube.
Yes
Yes.
What measurements units would be best to measure the amount of wanter in and eye dropper
The measure of the size of something in three-dimensional space is its volume.
I am not sure from your question means width, length, volume, area, or what, but the answer is going to most probably be 'meters' or 'kilometers'.
yes
The answer will depend on what characteristic of the grasshopper you wish to measure: its mass, its length, its volume, the frequency of its chirp, the frequency of the light representing its colour and so on.
milliter
29.57 ml
1,000
25740.81 ml
1cc = 1mL