开头句型：

1. In recent years, with the rapid development of... (近年来，随着...的快速发展)
2. It is universally acknowledged that... (人们普遍认为...)
3. It is beyond dispute that... (毫无疑问...)
4. There is a growing tendency that... (有一种日益增长的趋势...)
5. It is often the case that... (常常是这样的情况...)

结尾句型：

1. Therefore, it is not difficult to draw the conclusion that... (因此，不难得出结论...)
2. In summary, it is evident that... (总之，很明显...)
3. From the above analysis, we can see that... (从以上分析，我们可以看出...)
4. In view of the above discussion, it is safe to say that... (鉴于以上讨论，可以放心地说...)
5. Consequently, we should attach importance to... (因此，我们应该重视...)

以上句型可以用于BEC写作的开头和结尾，使文章结构更加清晰，观点更加明确。在实际应用时，可以根据具体题目和内容进行修改和调整。

希望这些句型能帮助你在BEC考试中取得好成绩！如有其他问题，欢迎继续提问。祝你好运！