it is close so then the blood can float in it nice and easy
Closed. It also has a water-vascular system. :)
Ok
You can tell if a clam is alive by observing if its shell is tightly closed or slightly open. If the clam is alive, it will try to close its shell tight when handled. A dead clam will have a gaping, gaping, or broken shell.
Clams are generally covered by a shell. It is a part of the clam's body, and it can open or close; when closed, it serves the purpose of protecting the clam from predators.
If it is dead it will be open therefore if it is alive it will be closed. Sometimes they are open but still alive, but if you tap their shell they close it.
Brown bear have a close circulation system
I am not sure how to get a clam to open naturally. The way I have known to open a clam is by hand.
fishes do have parallel circulation
Bivalve mollusks like clams hold their shells closed with their muscular bodies. They also have leathery "hinges" at the rounded part of the shell which help to hold the two halves together. These are similar to ligaments in higher animals. If you ever get a clam in the supermarket that is already open, that one is dead and you should not eat it.
Closed circulation is a phrase that the person asking this question doesn't know how to use in a sentence
YES
You have to go underwater which is left to Aphrodite and you have to find a clam. It opens and closes. Try to get the pearl (which is inside the clam) when the clam is open.