Question

directions: identify the choice that completes the text so that it conforms to the conventions of standard english.
1 ** the \songs\ of blue whales usually register at between 15 and 20 hertz—a nearly inaudible rumble on the edge of what the human ear can perceive. ______ one blue whale in the pacific has produced vocalizations registering more than 50 hertz! this finding is so unusual that some researchers have suggested the animal is actually a hybrid species.
1 (a) therefore, (b) moreover, (c) however, (d) for example,
2 ** in comparison with conventional agriculture, organic farming has several major advantages. it ______ nitrate leaching into groundwater. however, these benefits are counterbalanced by higher food costs for consumers and generally lower yields
2 (a) uses fewer pesticides, reduces soil erosion, decreasing (b) uses fewer pesticides; reduces soil erosion, and it decreases (c) uses fewer pesticides, soil erosion is reduced, also it decreases (d) uses fewer pesticides, reduces soil erosion, and decreases
3 ** most theories claim the moon formed out of the debris of a collision between the earth and a mars - sized object known as theia, which came together in orbit over a period of months or years. a new simulation advances a different ______ may have formed in a matter of hours, when material from the earth and theia was launched into orbit immediately after the impact.
3 (a) theory, though the moon (b) theory, though: the moon (c) theory; though, the moon (d) theory though the moon

Explanation:

Question 1

The first part talks about blue whales' songs usually being 15 - 20 hertz, and then a specific blue whale with over 50 hertz is mentioned. This is an example that contrasts with the usual case, so "however" (showing contrast) is appropriate. "Therefore" (cause - effect), "moreover" (addition), and "for example" (example of the same type) don't fit the contrast here.

The sentence lists the advantages of organic farming. The structure should be parallel. Option D has "uses...", "reduces...", "and decreases...", which are parallel verb - phrase structures. Option A has "decreasing" which is not parallel. Option B has a semicolon and an extra "it" which breaks parallelism. Option C has a mix of active and passive voice and breaks parallelism.

We need to analyze the punctuation and the relationship between the clauses. The first part is about most theories, and the second part is a different theory with a contrast. The correct punctuation is a comma after "theory" and then "though" to introduce the contrast. Option A has the correct punctuation and structure. Option B has a colon which is incorrect. Option C has a semicolon which is not needed. Option D lacks a comma after "theory".

Answer:

C. however,

Question 2