What type of data is measured by isoline maps

Q4. which are the major components of the environment?

Which continents lie only in the northern hemisphere

When volcanoes erupt, magma (hot, molten rock) rises toward the surface of the earth. as magma cools, solid rock forms. this rock contains substances from the interior of the earth. which of the following natural resources is likely to be plentiful near subduction zones where volcanic activity has occurred in the past?