*Question*
Tidal energy can be used to produce electricity, and spikes are forceful the tidal waves of electric current. Given these facts, what are used to produce current among the following options: - tube - waves - coal - streams - copper - rivers - engines - fibers
**Answer**
waves

*Question*
Nitrogen is found in proteins, nucleic acids, and chlorophyll, and nitrogen, as a gas, is colorless, odorless, and a generally inert element. Given these facts, what is found in proteins among the following options: - Something coming from a gland - Something that causes allergies - characteristics - Transfers energy - it keeps an organism warm - Chemical energy - that material's properties - a colorless, odorless gas
**Answer**
a colorless, odorless gas

*Question*
Melting is when solids are heated above their melting point, and ice is the solid form of water. Given these facts, when ice is what above its melting point that is melting. among the following options: - salinity - cooled - not - boiling - frozen - erosion - heated - an object
**Answer**
heated

*Question*
Immunodeficiency occurs when the immune system is not working properly, and many cancers can cause immunodeficiency. Given these facts, many _ can cause the immune system to not work properly. among the following options: - fever - bacteria - radiation - fungi - A drug. - Allergies - cancers - Toxicity
**Answer**
cancers