Passage: Joseph notices that a certain water weed in his aquarium, called Elodea, made bubbles of oxygen when he turned on the light in the aquarium cover. He set up an experiment to see if changing the color of the light bulb in his aquarium affected the number of
bubbles produced by the weed.
Question: Which variable would Joe want to keep controlled (keep the same) in order to insure a fair test in his experiment?
the type of water weed
the wattage of the light bulb
the time he had the light bulb turned on
all of the above

african americans demonstrated their newly found freedom by relocating often in search of relatives whom they had been separated from during slavery. others established schools to educate freed people and they built institutions such as churches and political organizations to advocate for their rights.

just did the assignment and the answer was #1 +2 n

i'm wiling to try and you : )

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them