Simplify the following text for a Grade 10 native English-speaking person.
Original: Borneo is surrounded by the South China Sea to the north and northwest , the Sulu Sea to the northeast , the Celebes Sea and the Makassar Strait to the east , and the Java Sea and Karimata Strait to the south .
Simplified: by the South China Sea to the north and northwest , the Sulu Sea to the northeast , the Celebes Sea and the Makassar Strait to the east , and the Java Sea and Karimata Strait to the south .