Given the sentence "A young south american child sits alone on a dirt and grass covered knoll along a ravine." is it true that "Several young south american children are sitting alone by a dirt and grass covered knoll by a ravine."?
Let's be accurate as possible and think first.
it is not possible to tell
A young South American child sits alone on a dirt and grass covered knoll along a ravine does not imply that they are sitting alone by a dirt and grass covered knoll by a ravine.

.

Thus, the answer is it is not possible to tell