What are two ways you can increase the frictional force between two objects?

What is used to keep track of the gamates and possible offsprings combination

Consider the classification levels of a human. eukarya ,animalia ,chordata ,mammalia ,primates, hominidae ,homo ,sapiens .which is the most specific taxonomic level in the classification system above? a sapiens b homo c hominidae d primates

Which macromolecule catalyzes chemical reactions this be considered enzyme chemical reactions thus he considering enzymes