How are musical instruments grouped? a: by their frequency b: by the wavelengths they produce c: by what they are made of d: by how they produce pitch

Musical instruments are grouped by how they produce the pitch.

Pitch is the highness or lowness of a tone.

co2reflects heat radiation back to earth buning coal and oil emits co2 globe warms

get the total number of pieces of fruit and divide it by 4 to get the average. the result is the answer to the problem. 14 total number of fruits and there are 4 members. 14 divided by 4 is equals to 3.5.