Answer:
Barter
Explanation:
Barter system is a kind of trade system of exchange in which the participles involving in the transaction directly exchange the services or the goods for other services or goods without the usage of medium of the exchange such as money.
Marcel and Charles are involving in barter system in which former exchanges the boat with the car of the latter.
<span>The leading cause of impaired surface waters in the United States is: </span><span>Pathogens.
Pathogens (or germs) are what can
produce diseases.
There are different types of pathogens: Bacterial (most
bacteria are not harmful for the human kind, but pathogenic bacteria can cause infectious
diseases); Viral (a few examples are influenza, or smallpox); Fungal (these
usually consume dead organisms but some might be harmful for humans too);
Prionic (these do not contain nucleic acids and cause diseases like, for
example, the bad cow diseases); Algal (caused by a type of green alga known as
Prototheca that lacks chlorophyll); and other parasites. </span>