The amount of available limits the number of trophic levels in a community. please help!!!

Which of these statements best describes the st. lawrence seaway? the st. lawrence seaway connects the st. lawrence river with the arctic ocean. the st. lawrence seaway provides an important trading route between the u.s. and mexico. the st. lawrence seaway provides an important trading route for the u.s, but has little value for canada. the st. lawrence seaway connects the great lakes, the st. lawrence river, and the atlantic ocean.

Common commercial benefits of microorganisms include synthesis ofa. insulin.b. antibiotics.c. aspirin.d. antibiotics and aspirin.e. antibiotics and insulin.

This is one form of rna that transports a specific amino acid to a ribosome during protein synthesis.