Which of the following is true about a light-year? A)It is a measure of time.

B) It takes one light-year for light from the Sun to reach Earth.

C) it takes one light-year for Earth to orbit the Sun.

D) It is a measure of distance.

plz answer ^w^
thx

What is the difference between an igneous, sedimentary and metamorphic rock

How do you think earths interior affects what is happening on the surface? 2. how do fossils support the continental drift hypothesis? 3. how does sea- floor spreading support the hypothesis of continental drift? 4.what do scientists observe when they studied the magnetic fields of rocks on the sides of mid-ocean ridges? 5. what is a tectonic plate ? 6. explain mantle convection 7.how can movements of the continents affect earths climate? 8. what occurs during drifting?

Which enzyme is responsible for “unzipping" the dna by breaking the hydrogen bonds between the nucleotides?