What carries oxygen to cells and takes carbon dioxide away

When trimming plants and vines: a.burn all the poisonous plants b.touch poison oak and poison sumac with your bare hands c.wear gloves d.cut as quickly as possible

Is it bad to have a headache all day long?

Which of the following could use reverse transcriptase to transcribe its genome? a) ssrnab) dsrnac) ssdnad) dsdna