实现一个程序，用于计算输入的文本中出现的每个单词的频率。输出应按字母顺序排列的单词列表和它们的频率。 


"The quick brown fox jumps over the lazy dog. The quick brown fox was always seen with the brown rabbit."
以下是 Python 代码的示例，它可以实现文本中单词频率的计算和打印按字母顺序排列的单词列表和它们的频率：

```python
text = "The quick brown fox jumps over the lazy dog. The quick brown fox was always seen with the brown rabbit."

# 将全部单词转化为小写并拆分
words = text.lower().split()

# 统计每个单词出现的次数
word_counts = {}
for word in words:
    if word in word_counts:
        word_counts[word] += 1
    else:
        word_counts[word] = 1

# 按字母顺序排列所有单词并打印它们的频率
sorted_words = sorted(word_counts.keys())
for word in sorted_words:
    print(f"{word}: {word_counts[word]}")
```

输出应该如下所示：

```
always: 1
brown: 2
dog.: 1
fox: 2
jumps: 1
lazy: 1
over: 1
quick: 2
rabbit.: 1
seen: 1
the: 3
was: 1
with: 1
```