Explanation

　　1.The correct answer is C

　　The error in this sentence occurs at (C), where there is a flaw in parallelism. The pronoun “they” should be removed so that the sentence contains three parallel verbs (“became,” “built,” and “developed”).

　　2.The correct answer is D

　　The error in this sentence occurs at (D), where there is an inappropriate verb form. The infinitive “to achieve” is needed to parallel the infinitive “to use.”

　　3.The correct answer is B

　　The error in this sentence occurs at (B), where there is awkward and unidiomatic phrasing. The awkward “that it has” should simply be “to have.”

　　4.The correct answer is A

　　The error in this sentence occurs at (A), where there is noun-noun disagreement. Instead of the singular “A meteorite,” the plural “Meteorites” is needed to agree with the plural nouns found later in the sentence (“particles” and “giants”). In addition, the singular verb “shows” should be changed to “show.”

　　5.The correct answer is C

　　The error in this sentence occurs at (C), where there is improper modification. It does not make sense to say that “Finland’s borders” are “One of the northernmost countries of Europe.” The proper noun “Finland” should be used instead.