Which compound would most likely be found in all living organisms

The image shows embryos of three vertebrate classes

The ruiz family is exchanging euros for us dollars. the exchange rate is 1 euro equals 1.35261 usd. since the ruiz family knows that usd are stated to the nearest hundredth of a dollar, they used the conversion ratio

There are fewer than 100 naturally occurring elements in the universe, but there are millions of different unified substances. explain how this can be true.