Apex domains cannot have CNAME records.
Question and response
Question
dig sv-en.RU. NS
Answer
sv-en.RU. 1 NS ns1.sv-en.RU.
sv-en.RU. 1 NS ns2.sv-en.RU.
Authority
The response has no authority records.
Additional
ns1.sv-en.ru. 1 A 134.19.151.187
ns2.sv-en.ru. 1 A 134.19.151.186
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0