In the passage, the two portions in boldface play which of the following roles?【小站备考】

It is imperative that rice fields are flooded at the proper time. Rice will grow less productively if flooded before reaching 4 inches. Flooding should begin when the rice reaches a height of 4 to 6 inches. Floodwaters will then provide a favorable environment for rice growth, help control weeds and stabilize soil ammonium nitrogen. In order to aid weed control of both broadleaf and grass, and to reduce nitrogen losses, establish the first flood within 3 to 5 days after pre-flood nitrogen applications. The depth of the flood is as important as its timing. The flood should be no deeper than 6 inches; deeper water interferes with proper tillering of rice. Generally, a 2-inch flood on the upgrade side will prevent too-deep water if the levees were properly surveyed.

Question 4

In the passage, the two portions in boldface play which of the following roles?

A. The first states the conclusion to the main argument of the passage; the second serves as an illustration of the secondary conclusion.

B. The first presents the reasoning that the argument as a whole opposes; the second supports the conclusion of the argument.

C. The first provides support for the argument as a whole; the second supports an objection to that argument.

D. The first serves as the reasoning behind the initial conclusion; the second serves as the reasoning behind the secondary conclusion.

E. The first states the conclusion of the secondary argument; the second provides support for that conclusion.

我的答案： 无

Question 4