Q19: Plankton generally thrive in areas of the ocean with sufficient concentrations of certain nitrogen compounds near the surface, where plankton live. Nevertheless, some areas, though rich in these nitrogen compounds, have few plankton. These areas have particularly low concentrations of iron, and oceanographers hypothesize that this shortage of iron prevents plankton from thriving. However, an experimental release of iron compounds into one such area failed to produce a thriving plankton population, even though local iron concentrations increased immediately.
Which of the following, if true, argues most strongly against concluding, on the basis of the information above, that the oceanographers’ hypothesis is false?
- Not all of the nitrogen compounds that are sometimes found in relatively high concentrations in the oceans are nutrients for plankton.
- Certain areas of the ocean support an abundance of plankton despite having particularly low concentrations of iron.
- The release of the iron compounds did not increase the supply of nitrogen compounds in the area.
- A few days after the iron compounds were released, ocean currents displaced the iron-rich water from the surface.
- The iron compounds released into the area occur naturally in areas of the ocean where plankton thrive.
题目问哪个反对了海洋学家的推测是错误的结论,也就是说选支持他的观点是对的选项了. 搞不明白,给出的答案是d,怎么正确了. 我选了e Q28: Which of the following most logically completes the argument?
A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants. Agronomists studying the herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert. Possibly, therefore, the herb’s high histidine production is what allows it to grow in metal-rich soils, a hypothesis that would gain support if ______.
- histidine is found in all parts of the plant—roots, stem, leaves, and flowers
- the herb’s high level of histidine production is found to be associated with an unusually low level of production of other amino acids
- others of the closely related group of plants are also found to produce histidine in large quantities
- cultivation of the herb in soil with high concentrations of the metals will, over an extended period, make the soil suitable for plants to which the metals are toxic
- the concentration of histidine in the growing herb declines as the plant approaches maturity
晕...给出的答案是e,我认为这个选项不相关,我选了d 请大家指教 | 
