@Yunyao_Li
I just took a quick look at your attached file. There are a couple of weird characters inside your URL, in particular when defining target="_blank" see highlighted below. Could you remove the weird chars and try again to see if it works? What are you using to edit the CSV file? I am wondering how these chars got in there…
Smoking is a known risk factor for lung disease. According to several <a href=“http://www.tobaccoinduceddiseases.org/COVID-19-and-smoking-A-systematic-review-of-the-evidence,119324,0,2.html#cit0012” target="_blankâ€>studies on COVID-19 patients, former and current smokers were among the most severe cases (those needing mechanical ventilation and intensive care support, or who died).
For more information on who is at higher risk, please check </a href=“https://www.cdc.gov/coronavirus/2019-ncov/specific-groups/high-risk-complications.html#who-is-higher-risk” target="_blank">CDC website.