Q: Studies in Individual Languages とはどういう意味ですか?
A: It is a class about studying a new language. I'm guessing it is a class that involves focusing on certain languages instead of groups or families of languages. I will come back with a better answer hopefully

Where did you find this phrase?


Q: Studies have demonstrated that ... と According to studies, it has been demonstrated that.. はどう違いますか?
A: @jingeon nothing


Q: I'm a English Studies graduate from the Universidad de... は 英語 (イギリス) で何と言いますか?
A: " English...."
Q: Studies
Studies は 英語 (アメリカ) で何と言いますか?
A: QAの全文をご確認ください


Q: Studies have shown that Notsuke Peninsula is sinking at a rate of about 1.5 centimeters per year due to rising sea levels and drifting sand deposits caused by global warming. この表現は自然ですか?
A: Very well-written and natural.

To make it better, I would say 'due to rising sea levels and coastal erosion caused by global warming.' Coastal erosion is the official name for 'drifting sand deposits,' so it sounds a bit better :)
Q: Studies have found that robots can trigger human emotions and fill an almost identical emotional niche.

What is niche?
A: In this context I would say that “niche” means the action of showing emotion towards something
Q: Studies also showed the increase of childhood cancers such as leukemia for the residents who is living near the nuclear power plant. この表現は自然ですか?
A: If "increase of childhood cancers" has not already been mentioned, use "an increase of childhood cancers" rather than "the increase of childhood cancers"
Q: Studies show that the new strategy is not ( very) effective as the previous one.

Why is (very ) wrong in this sentence?
A: The sentence with (very) would work if the line ended at effective. It just does not sound as natural and does not flow as well. However you could replace the (very) with (as) and it would have a similar effect.
Q: "Studies are not only the grades" この表現は自然ですか?
A: I'm not sure what you are trying to say do you mean studying is not just about the grades you make?