Which problem do you think contributes most to water scarcity?

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.

The image shows the evolution of a species of fish. a few fish from a population developed different social behaviors and evolved into different species. two fish according to the image, the fish underwent . the new species of fish had mating seasons that were different from that of the original fish. because of the differences in mating seasons, the fish underwent reproductive isolation. this mode of isolation would be .

Astudy by solloch and et. al., in 2017, gives the map above which shows the frequency of alleles with a ccr5-delta32 mutations over 87 different countries. this mutation deletes the presence of a co-receptor (ccr5) on the outside of human t-cells (lymphocytes). some viruses, such as the one responsible for the black death and human immunodeficiency virus (hiv), require this receptor for attachment to host cells during the infection process. the black death was an epidemic that passed over northern europe during the 14th century killing nearly 60% of europeans. according to this information, which explanation best explains why northern europeans show a greater immunity for hiv than some other parts of the world?