Passage II

In August, the ozone (O3) content of the stratosphere above Antarctica begins to decrease, reaching a minimum around October 15. Over this period, winds surrounding this ozone hole keep it isolated from adjacent areas where the air has greater O3 content. In late October, the winds weaken, causing the O3 content of the air in the ozone hole to increase again as this air mixes with the air from adjacent areas. Figures 1 and 2 show how the air temperature and O3 partial pressure (a measure of O3 content), respectively, changed with altitude in a portion of the stratosphere above a location in Antarctica on September 15, October 15, and November 15, 2000.

Figures adapted from O. Troshichev and I. Gabis, "Effects of Solar UV Irradiation on Dynamics of Ozone Hole in Antarctica." ©️2005 by Elsevier, Ltd.

9. Consider the information in the passage about the annual changes in content in the stratosphere above Antarctica. Based on this information and Figure 2, on October 1, 2000, at an altitude of 18 km above the location in Antarctica, the partial pressure would most likely have been:

Answer and Explanation

Your Answer is

Correct Answer is A

Explanation

The question asked about the O3 partial pressure on Oct. 1st, which should be between Sep. 15th and Oct. 15th. When the altitude is 18 km, the value should not be greater than the partial pressure on Sep. 15th, only less than 4 mPa meets