Q6

[dayani_elika]

For this question I chose E at first but I was stuck between B and E. Why is E incorrect? How do we know B is correct? Thank you.

[rinagoldfield]

This a really tricky passage. I see why you found it challenging.

(B) is supported by lines 23-29. These lines tell us that gas surges mean that a pump "can no longer impart enough energy to import the crude mixture." We can infer that this lack of energy translates to a lack of efficiency.

(E) is unsupported. The first paragraph mentions the risk of explosions, but the passage never tells us what increases this risk. So we can’t safely connect risk of explosion to a change from liquid to gas.

(A) is extreme. Sure, a "surge" of gas might harm the efficiency of the pumps, but that doesn’t mean pumps require a complete absence of gas to operate smoothly.

(C) is unsupported. It describes a shift from solid to liquid, while the passage describes a shift from liquid to gas.

(D) is contradicted. The liquid-gas ratio is essential to pump efficiency. We know that sudden shifts in this ratio cause the pumps to peter out.

Hope this helps.