Question

finding bombs in germany
during world war ii, american and british forces dropped millions of tons of bombs on
german cities. nearly ten percent of the bombs never exploded. the war ended in 1945,
but more than two thousand tons of unexploded bombs are still found in germany each
year. before any construction project is undertaken, the site must be checked for
unexploded bombs. buried bombs are often discovered. for this reason, germany has a
special force of firefighters and police officers, called the kmbd, to defuse and remove
these bombs. even though the war has been over for seven decades, the kmbd is one of
the busiest bomb squads on the planet.
what is the main, or central, idea of the passage?
because there are so many unexploded bombs in germany, the country has a
special force trained to defuse them.
because there is so much construction in germany, the country has a special
force trained to defuse bombs.
almost ten percent of the bombs dropped on germany during world war ii
never exploded.

Explanation:

The passage first mentions that during World War II, many bombs were dropped on Germany and a significant portion (nearly ten percent) didn't explode. Then it states that even decades after the war ended (1945), these unexploded bombs are still found each year. And because of this situation (the presence of many unexploded bombs), Germany has a special force (KMBD) to defuse and remove them. The second option about construction is not the main reason as the text emphasizes the bombs' existence. The third option is just a detail, not the central idea. The first option correctly ties the cause (many unexploded bombs) to the effect (special force to deal with them), which is the main idea.

Answer:

Because there are so many unexploded bombs in Germany, the country has a special force trained to defuse them.