Mr. and mrs. tew attended this summer band concert to her their son play his violin. when they sat down in their seats, they noticed that there were dead moments. that is, places in the music when they could not hear anything! they decided to move and sit directly in front of the band in the third row. how can you explain the dead spots they experienced?

a: some sound waves cancelled each other out.

b: sound waves reflected off of the ceiling and walls.

c: the sound waves underwent constructive interference.

d: some of the students stopped playing for a few seconds.

the answer is d.) homologous; have mammary glands

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds