Could life as we know it exist if the air on earth only contained oxygen?

Although there are a limited number of amino acids many different types of proteins exist because..

Ascientist wants to determine the effect of a new type of gasoline. he fillsone car with normal gasoline and another identical car with the new gasoline.which is the control group? a. the new type of gasolineb. the car with the normal gasolinec. the car with the new gasolinethe amount of gasoline usedd. the amount of gasoline used

Read the sentence. “yesterday we arrived late for the outdoor concert in the city gardens.” which words in the sentence are adverbs? a. late; city b. yesterday; outdoor c. yesterday; late d. outdoor; city