What are the variance (to 2 decimals) and standard deviation (to 4 decimals) for the number of these tweets with no reaction?

Which of these terms are associated with communication between neurons? chemical signals, electrical signals, synapse chemical signals, synapse, neurotransmitters synapse, electrical signals, chemical signals synapse, electrical signals, neurotransmitters

What is another way name for bd? cf, bd, cf, be

How was the sat? what type of questions for math, writing and reading. did anyone get a near perfect score and if so how long did it take to study. i am very stressed and want to get at least a 1450.