Comet tails . always point toward the sun
are only seen when comets are near the sun
are caused by intense air friction
are made of carbon and magnesium

During the day, plants produce by splitting water molecules in the light-dependent reactions of photosynthesis. at the same time, plants use cellular respiration to produce some of the needed by the light-independent reactions to make sugars. during the night, plants produce because takes place.

Which substance contains thylakoids? a) nadph b)atp c)stroma d)chloroplast

Lumps of iron and manganese ore called can be harvested from the seafloor near underwater volcanoes.