Instruct: Classify the given review into positive or negative sentiment.
Query: Too many unanswered questions

"The Day After Roswell" by Philip Corso is either one of the most significant books of the 20th century or a complete waste of time. Corso, a former high-ranking military officer, claims that he spearheaded the government's supersecret effort to analyze the wreckage of an alien spacecraft and apply the extraterrestrial technology to US industry. Among other items, fiber optics and integrated circuit chips are allegedly the fruits of Corso's efforts. Corso's account is meticulous but leaves many questions unanswered. The author verifies the existence of the infamous, oft-doubted MJ-12 working group and offers the possibility that the "aliens" found at Roswell were in fact time travelers from Earth's own future, raising some bizarre questions: if the "aliens" came to 1947 using technology which we in turn injected into contemporary industry, then where--or, more accurately, when--did the technology come from in the first place?