本题目来源于试卷: IB ESS Unit 1 Foundations of ESS，类别为 IB环境系统与社会
[单选题]
Figure: Levels of zi (1e o6i/kzjflnc in se kc;xq9k(m/(4o hn;(a xgbc i-x o- xag-2hhzzawater at Palmira Beach
[Source: adapted from Tovar-Sanchez, A., et al. (2013) Sunscreen products as emerging pollutants in coastal waters.
PLoS ONE,8(6). Retrieved June 1, 2023 from https:// doi.org/10.1371/journal.pone.0065451. Copyright under CC BY 4.0]
Some sunscreens contain chemicals such as zinc (Zn) that may be toxic to some marine life. The figure shows the concentration of zinc found in the seawater at Palmira Beach on Majorca Island over the course of a day.
Suggest the most likely conclusion that could be made from this graph.
A. Zinc is harmful to the organisms found in the surface microlayer.
B. Zinc mixes freely in the water after it washes off the skin.
C. Zinc is absorbed and rendered harmless during the night.
D. The total concentration of zinc in the surface microlayer is highest soon after many people will have started using sunscreen.
参考答案: D
本题详细解析:
Option D is correct as we see on the graph that both zinc in the surface y. *y)esda czs6d/:j tmicrolayeszs*:ajty)/ y dd.c6 er as in the subsurface layer is highest at 14:00. Most people use sunscreen when the sun is high in the sky. It is highest at noon, 2 hours before the highest level of zinc in the water.
Option A is true according to the text but the graph does not say anything about it so it is incorrect.
Option B is incorrect because the data clearly show that there is much more in the top surface microlayer than in the layer below that (subsurface). This is most likely due to the zinc being suspended in the fatty substances in the sunscreen that float.
Option C is incorrect because we can see that even in the evening and early morning there is still zinc in the water.
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