What causes the abyssal plain?

How wide is the widest part of river severn? What is one town that is near a desert? What is a desert wash? Which statue from Florida is located in statuary hall and what did he invent? What is the animal life cycle of Mount Everest? Where was celebrex commercial with the lady swimming in clear lake water filmed? Where is the Broad River Antique Power Association in Gaffney South Carolina located? What is a 4 to 1 ratio? Why do people go to Victoria Falls? How is the Lut Desert? Will apophis kill everyone in the world? Can a tsunami flood a coastal river? What is the canal in Ontario Canada that connects Lake Erie to Lake Ontario? Did the Japanese attempt to rebuild the great pyramid? How do animals survive in the coral reef? How much did the Davin stand cost to build? What challenges did Hercules face when he went to get the golden feece? How many lakes in Mexico not just major lakes? Which continent that borders the Pacific Ocean is NOT affected by the Ring of Fire? Why people died a lot during construction of the Panama canal?