Charles Keeling’s work at the National Oceanic and Atmospheric Administration (NOAA) Mauna Loa Observatory paved the way to understanding how human activities can lead to global warming. Which greenhouse gas did Charles Keeling measure at the observatory?
A)carbon monoxide
B)methane
C)nitrous oxide
D)carbon dioxide

Type the correct answer in the box. use numerals instead of words. fiona has a lovely flower bed in her yard. she wants to add a fence along one side of the flower bed. the fence material is sold in meters. fiona knows that her flower bed is 200 centimeters in length. how much fencing material does fiona need in meters? fiona needs meters of fencing material for her flower bed.

What occurs to the cell during mitosis

How do the evolutionary chart and the video support the claim that all living things are made up of cells?