题目

阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。Anexperimental antiviral medication might help fight the new coronavirusAsingle case study isn't enough to prove anything. It's not clear if the medicationcalled remdesivir, actually helped the patient, or if his improvement was a coincidence.But it's one of a few drugs, (include)a combination of anti-HIV drugs, doctors think might help patients with the newcoronavirus.Remdesivirwas developed by the pharmaceutical company Gilead as a treatment Ebola. It's a broad-spectrum antiviral drug, andit block在直角三角形ABC中，∠ACB=90°，CD是斜边AB上的中线，且BC=CD．则∠B=（　　）A．30°B．45°C．60°D．90°