Which gas in Earth's atmosphere helps living things make proteing? O oxygen
O nitrogen
water vapor
O carbonoxide

Explain two reasons you think it is important for scientists to search for new ways to treat cancer

For a to be healthy, it has to have lots of different kinds of plants and animals. all of the different types of plants and animals in an ecosystem. name four types of ecosystems from those listed in the video. b) c) d) most living things live here. all living things depend on how an ecosystem like a game of sticks? why should we build new buildings on existing land? name four extinct species from those listed in the video. b) c) d) the best way to wipe out a species is to the largest ecosystem in the world is this percent of the world is covered by water. how many of all species in the world live in the ocean? list five things you can do to increase biodiversity. b) c) d) e) how many species are we losing per hour?

Compare the depth of field when focusing with low power and high power. which power has the greater depth of field?