shell:$ nslookup -timeout=2 -retry=1 'duolingo.cn'
Server:		1.1.1.1
Address:	1.1.1.1#53

Non-authoritative answer:
duolingo.cn	canonical name = 1sru0i2f6syq309n.aliyunddos1001.com.
Name:	1sru0i2f6syq309n.aliyunddos1001.com
Address: 110.75.170.67