function concatenate_replace(str) {
str = str.substring(11).replace("that","THAT").replace("technologies","");
return str;
}
let str = "JavaScript is a programming language that is one of the core technologies of the World Wide Web";
str = concatenate_replace(str);
console.log(str);
/*
run:
is a programming language THAT is one of the core of the World Wide Web
*/