bridges connect land masses
No. The seven continents did not all connect, because Australia did not touch them.
7 continents
Europe and Asia.
Assuming that each bridge can connect at most two vertices, you will need at least 4 bridges to connect seven vertices. Conversely, two bridges will connect at most four vertices.
The land of dry deserts that bridges two continents is Beringia. This land connects America and Asia through Siberia and Alaska.
Europe and Asia
About 400 bridges connect the 118 islands that make up Venice.
Alaska and Siberia
brooklyn
Most bridges are manmade, built in the location where they are required. Some natural bridges of rock or timber exist in wilderness areas.
There are 2 continents that touch Asia, they are the continents of Europe and Africa. Long ago, North America also bordered Asia through ice bridges.