What is a bachan dune?

How deep is the river Trent? Why does geosphere interact with the grand canyon? Why do people celebrate the summer solstice at Stonehenge? What whether do rainforest have? Which states have shorelines on the Atlantic ocean? How much are forest fires destroying the rainforest? How did Egyptians prepare for times when the Nile did not flood enough and crops couldn't and grow? How is the Great Salt Lake related to North American deserts? What is the name of the sea port of Athens? Why is this egpyt country famous? Glacial runoff and what provide the water for the large rivers of India? Where is the Zitelman Scout Museum in Rockford Illinois located? What was the Grand Canyon before it was the Grand Canyon? What landmark begins with the letter j? What famous sea stumps in the UK are there? What is the absolute location of Niagara Falls New York? How come mangroves aren't usually in fresh water? Where did people worship at Stonehenge? Why is it difficult to transport goods on the rivers in Africa? How many miles from lexington KY to ocean city NJ?

What is a bachan dune?