Jump to level $1$

CREATE TABLE Country $($ Name VARCHAR $(15),$ TLD CHAR $(3)$ NOT NULL, IndepYear SMALIINT, Continentcode CHAR $(2),$ ISOCOde$3$ CHAR $(3)$ NOT NULI, continent VARCHAR $(8)$

;

Which columns can contain NULL values?

Name

TLD IndepYear

ContinentCode ISOCode$3$

Continent