Which group of animals has a closed circulatory system featuring a single circuit and two heart chambers?

mammals

tunicates

amphibians

fish

birds

In which case would a scientist choose to use a dissecting microscope rather than a compound microscope

In 2015, about ten percent of total u.s. energy consumption was from renewable energy sources. renewable energy plays an important role in reducing greenhouse gas emissions. when renewable energy sources are used, the demand for fossil fuels is reduced. sanjay and his family want to cut back on their use of non-renewable resources at home. they are thinking of an alternate way to heat their home without adding more greenhouse gases or pollutants to the environment. which renewable resource would not fit into their plan? a) solar power b) burning wood c) constructing a wind turbine eliminate d) generating hydroelectric power

This is collection of data made by comparing objects in standard units. in science, the units are metric.