Concept:Use syllogism rules: All A are B and Some C are A implies Some C are B, and its converse also holds.
Explanation:Given: All windows are needles. Some trees are windows.
From "Some trees are windows" and "All windows are needles", we get: Some trees are needles.
Conclusion I states that, so it follows.
The converse of "Some trees are needles" is "Some needles are trees", which is conclusion II (assuming it is "some needles are trees").
Since "some" statements are reversible, conclusion II also follows.
Thus both conclusions follow.
Answer:Both I and II follow.