【单选题】Scientists studying the activity of the living brain with widely used new imaging techniques have been missing some of the earliest steps in brain activity because those changes are subtle and are mas...
A.
those changes are subtle and masked by some reactions
B.
subtle changes in blood flow began earlier
C.
the imaging techniques are out of place
D.
the flow of blood to increase to an area of the brain is slow
【简答题】Footnotes or _________ are not frequently used in _________ writing as they are in the ___________ and the ______ sciences. Natural scientists most often use the name-year system.