If one puts ones ears to the steel rail, the sound of a coming train can be heard even when the train cannot be seen. One can conclude from this observation that
(1) sound travels faster in steel than in air.
(2) amplitude of sound in the rail is much larger than in air.
(3) sound can travel larger distances in solids than in air.
(4) quality of sound in rail is better than in air.
The reasonable conclusions are

Options

A. 1 and 3
B. 1 and 2
C. 2 and 3
D. 2 and 4

Explanation

To solve the question, we need to analyze the observations made when one puts their ear to a steel rail to hear the sound of an approaching train.

### Step-by-Step Solution:

1. **Understanding Sound Propagation**: Sound travels through different mediums (solid, liquid, gas) at different speeds. In general, sound travels fastest in solids, slower in liquids, and slowest in gases.

2. **Evaluating Option 1**: The first option states that "sound travels faster in steel than in air." This is true. Sound travels approximately 15 times faster in steel than in air. Therefore, this option is correct.

3. **Evaluating Option 2**: The second option claims that "the amplitude of sound in the rail is much larger than in air." This statement is incorrect. The amplitude of sound refers to the loudness of the sound, and while sound can be transmitted better in solids, it does not mean that the amplitude is larger in the rail compared to air. Thus, this option is not reasonable.

4. **Evaluating Option 3**: The third option states that "sound can travel larger distances in solids than in air." This is also true. Sound can travel longer distances in solids due to less energy loss compared to air. Therefore, this option is correct.

5. **Evaluating Option 4**: The fourth option suggests that "the quality of sound in rail is better than in air." While sound may be clearer in solids due to less interference, the term "quality" is subjective and can depend on various factors. Thus, this option is not definitively correct.

6. **Conclusion**: Based on the evaluations, the reasonable conclusions are options 1 and 3.

### Final Answer:
The reasonable conclusions are (1) sound travels faster in steel than in air, and (3) sound can travel larger distances in solids than in air.

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