It's asking for how thick it is not the length of it. So the obvious answer is not centimeters or meters. It would be millimeter.
mm
a millimeter
In meters.
In my opinion, the best unit for measuring the weight of a pencil would be grams. :)* * * * *Grams may be used for measuring mass, but that is not the same as weight. The best unit is probably a milliNewton.
There is really no such thing as a "liquid" unit. The unit of measure is for the VOLUME of something. The best unit for measuring the volume of a human bathtub would be the "Litre".
You need an Engineer's Micrometer which will be accurate to either 1 hundredth of a MILLIMETRE, Or to 1 thousandth of an INCH.
The thickness is of the order of a millimetre so a smaller unit - a micrometre, perhaps - is suitable.
Millimeters, or centimeters.
millimetres
mm
You would use millimeters (mm) to measure the thickness of a house key, as it is a small unit appropriate for measuring such dimensions.
The best unit is a litre.
Micrometres.
The best unit for measuring the length of a pencil is inches.
You would typically use millimeters (mm) to measure the thickness of a coin. This unit is commonly used for measuring small distances or thicknesses.
Gram
a millimeter