------
## 最终结论
```python
def merge_dict(dict1, dict2):
    merged = dict1.copy()  # Start with the first dictionary
    merged.update(dict2)   # Update with the second dictionary
    return merged

# Test cases
assert merge_dict({'a': 100, 'b': 200}, {'x': 300, 'y': 200}) == {'x': 300, 'y': 200, 'a': 100, 'b': 200}
assert merge_dict({'a':900,'b':900,'d':900}, {'a':900,'b':900,'d':900}) == {'a':900,'b':900,'d':900}
assert merge_dict({'a':10,'b':20}, {'x':30,'y':40}) == {'x':30,'y':40,'a':10,'b':20}
```