Select all of the answers that apply.
which of the following are sources of biomass?
wood
the sun
manure
water
paper
trash
food crops

I believe wood and food crops are the correct answers.

The biomass is the plant or animal product or waste which is not used for eating or feeding and is used for generation of energy (in form of heat or other forms). so biomass if source of energy obtained from biological products.

In the given options

Wood : its waste can be used as biomass

Sun : it is the source of solar energy

Manure: it is decomposed product biological material used in agriculture

Water: it is not a source of energy directly

paper : it is also a product of wood but is not considered to be biomass

trash : it depends that what is present in trash and how it can be used

food crops: yes these are biomass

The value 1 place to the right of the decimal point is the tenths digit. 
The value 2 places to the right of the decimla point is the HUNDREDTH digit. 

We are accurate to the hundredth digit. (8.7"5") 

The smallest marking on the instrument must be the 1/100 mL place. 

1/100 mL