You post an incomplete sentence. All I can tell is blank 1 and blank 2 are opposite to each other. But you can’t say depending on foreign sources is a bad or good thing by using your own knowledge. No evidence to judge.
This is a double possibility question. Since “though” indicates a contrast, we have two options.
If the dependence increases, it’s a bad thing (first blank), then the second blank will be something good.
Dependence on foreign sources of heavy metals, though increasing(bad), remains good, for United States foreign policy
And if the dependence decreases, it’s a good thing (first blank), then the second blank will be something bad.
Dependence on foreign sources of heavy metals, though decreasing (good), remains bad, for United States foreign policy