Which of the following contaminants is radioactive?
a. benzene b. plutonium c. mercury d. lead

Where would you expect to see seedless plants, such as ferns and mosses? a. in a botanical museum, because they are all extinct b. low and close to the ground in a moist environment c. climbing high while circling the branches of another plant d. deeply rooted in a forest with a trunk that reaches 20 meters or more

Draw the structure of dna nucleotide with adenine as nitrogenous base

Which organelle breaks down sugar molecules that supply energy to the cell ?