All oraganisms can not tolerate a wide range of salinities.

Answer

### Step-by-Step Solution:

1. **Understanding the Statement**: The question states that "All organisms cannot tolerate a wide range of salinities." We need to determine if this statement is true or false.

2. **Defining Salinity**: Salinity refers to the concentration of salts in water. High salinity means that the water has a lot of dissolved salts, which can affect the organisms living in that environment.

3. **Habitats of Organisms**: Different organisms inhabit various environments:
- Some organisms live in freshwater (low salinity).
- Others live in marine environments (high salinity).
- Some organisms are terrestrial (land-dwelling) or aerial (air-dwelling).

4. **Tolerance to Salinity**: Not all organisms can tolerate high salinity. For example:
- Freshwater organisms may struggle to survive in high salinity due to osmotic stress.
- Terrestrial organisms may not have adaptations to deal with saline environments.

5. **Conclusion**: Since the statement claims that "all organisms cannot tolerate a wide range of salinities," and given that many organisms have specific salinity tolerances, the statement is **true**.

6. **Final Answer**: The statement is true; not all organisms can tolerate a wide range of salinities.