要彻底删除电脑和手机QQ聊天记录，可以采取以下步骤：

对于电脑上的QQ聊天记录，可以登录QQ官网，在主界面点击“消息”，然后右键点击要删除聊天记录的群或者联系人，选择“删除消息记录”，再点击“全选”，最后点击“确定”即可。

对于手机上的QQ聊天记录，可以参考以下步骤：

1. 卸载手机QQ软件：这样会删除所有聊天记录和相关数据，但此方法过于激进，慎用。

2. 使用第三方软件删除：如果想删除部分聊天记录但不希望同步到其他设备，可以使用第三方软件进行操作。

需要注意的是，一旦删除的聊天记录和文件很难恢复，因此请慎重操作。如果还有其他疑问，可以咨询腾讯客服。

Dear [Buyer's Name],

I hope this message finds you well. We are writing to introduce our high-quality rose garden products and express our desire to explore possible business opportunities with your esteemed company.

Our rose garden is carefully cultivated using the latest agricultural techniques to ensure the growth of healthy and disease-free plants. With a wide variety of species and vibrant colors, our roses are known for their beauty and durability, making them the perfect addition to any garden or landscape.

Our company is committed to providing exceptional customer service and ensuring a smooth transaction process. We offer competitive pricing and comprehensive shipping options to meet your specific needs. Additionally, we maintain an extensive inventory and are able to provide rush orders upon request to meet your deadlines.

We would love the opportunity to discuss how our products can complement your current offerings and create a unique and alluring rose garden experience for your customers. Please feel free to contact us at your convenience to schedule a meeting or to request additional information.

Thank you for considering our products and services. We look forward to the possibility of working with you.

Best regards,

[Your Name]