For the engineering information platform, which is the best?

if it's not the virtual number, I personally think that the information content is the best. But it's useless to have a contact person, because the virtual number makes me unable to contact. How can I do business? I can't even add a WeChat to send a text message.

Later, I had to choose other platforms. I found that the information content was a little different, but the gap was not very big. Anyway, I can't do business by the contacts provided by your website. As long as the project is suitable, I can find many ways to cut in the clues provided.

just choose something with high cost performance, such as Tiangong. com and Zhongce.