Complete the sentences with words that are punctuated and spelled correctly. The "Big Dig" (the Central Artery/Tunnel Project) has been complex and challenging. Located in
Massachusetts, this tunnel is
eight lanes wide and more than three miles long. What is most amazing about this tunnel is that it is constructed under a major highway
and skyscrapers located in Boston's financial district.
Construction crews used "clamshell excavators" during this dig. These machines carved narrow
and then a special
substance was pumped into the trench to keep the dirt from caving in.
steel beams were lowered Into the trench and
concrete was pumped in.