What's up these organisms has an exoskeleton?

The fish shown above is a tarpon. it is a fast-swimming and powerful open-water fish. its closest relatives, oddly, are burrow-dwelling conger eels that stay on the bottom. both eels and tarpon developed from snake-like larvae that float in the plankton during the first stages of life. once they mature, tarpon and eels are not found near one another in the ocean. the tarpon and the eel illustrate all of the following except

When lactate builds up in a runners muscles it causes a burning sensation what causes this to occur

The “ecological footprint” left by a citizen of a developed nation is about four times larger than that left by a citizen of a developing nation. why is this the case?