Stop swinging the corpse and focus on digging the grave!

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

What is the most abundant vertebrate on earth?

Fill in the blank with the correct sphere label. a: ⇒ geosphere b: ⇒ biosphere c: ⇒ hydrosphere