Apex domains cannot have CNAME records.
Question and response
Question
dig bs.com.ru. NS
Answer
bs.com.ru. 5 NS ns.bs.com.ru.
bs.com.ru. 5 NS ns2.bs.com.ru.
Authority
The response has no authority records.
Additional
ns.bs.com.ru. 5 A 79.110.240.2
ns2.bs.com.ru. 5 A 79.110.255.18
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0