Final answer:
The question regarding the river source located at approximately 100 degrees east longitude and 35 degrees north latitude likely refers to a notable river, potentially the Yellow River in China.
Step-by-step explanation:
The student's question is asking for the identification of a river source located at 100 degrees east longitude and 35 degrees north latitude. To determine the name of the river, one must consult a map or geographic database that shows the origins of rivers along with their coordinates.
However, one cannot provide an accurate response to this inquiry without access to the appropriate resources or verifiable data. A river known to have its source in the general region described could be the famous Yellow River (Huang He) in China, but confirmation must be obtained before stating this as a definitive answer.