A graduated cylinder is used to measure volume of a liquid.
Most of the earth's water is liquid.
A graduated cylinder can be used to measure volume of water.
What can be used to measure the volume of water?

[1] Spring Loaded Cylinder
[2] Tape Measure
[3] watershred
[4] Earth orbiting the Sun
[5] an electron lens
[6] a graduated cylinder
[7] an electron microscope
[8] Ruler