The Thames, my dear child.
*** River Thames***
not ''Thames River''
Answer:
Japan practiced a strict isolation policy up until the signing of the Kanagawa treaty on March 31, 1854. This opened the borders of Japan and forced them to trade with the rest of the world. Japan feared the escalation of the situation and succumbed to the United States and opened its ports for trade. After that Japan modernized and grew in power.
I would say that in very fast moving water such as in a river, the cobble size could be transported because cobbles are 64-256mm so are quite big and in a quiescent stream won't move much but in a freshet say in a steep mountain stream they can be rolled along such as I observed in the local streams at a mining town during the Hurricane Fifi in Honduras in 1974.
An island is a piece of land surroinded by water. Hawaii and The Keys are examples
