Question 65

Sea levels around the world are rising because water expands when it warms.

This statement represents an assumption because it presupposes a cause-and-effect relationship between warming ocean waters and rising sea levels without providing direct evidence within the passage.

A) Warming ocean waters will put all fishers out of business.

This option is incorrect as it makes a definitive prediction about the impact of warming ocean waters on the fishing industry. It is not an assumption but rather a conjecture that lacks sufficient supporting evidence, making it too absolute.

B) Sea levels around the world are rising because water expands when it warms.

This statement is the correct answer as it reflects an underlying assumption about the relationship between temperature increases and the physical properties of water. It is assumed to be true in the context of the passage, forming a foundational basis for discussing the implications of rising sea levels.

C) Ocean water is combining with water from melting land glaciers.

While this statement describes a process that may be occurring, it is not an assumption but rather a fact that could be supported by external evidence. It does not imply a necessary connection to a broader implication regarding sea level rise.

D) Rising sea levels are affecting coastlines and ecosystems in many places.

This option states an observation rather than an assumption. It reflects an effect that is likely supported by empirical data rather than positing a necessary underlying belief or premise that must be accepted without proof.

Conclusion

Option B is definitively the correct answer because it encapsulates an assumption that connects warming ocean temperatures to sea level rise through the principle of thermal expansion. The other options either state observations, predictions, or processes that do not rely on the same underlying reasoning, thereby failing to meet the criteria for an assumption.