Answer:
Using python 
print("Welcome to computer Science")
Using JavaScript,
console.log("Welcome to computer science")
document.write("Welcome to computer science")
Explanation: 
There are various kind of coding language use to output a string. The text "Welcome to computer science" can be outputted using different backend languages .Example of this languages includes Python, JavaScript, Kotlin, Java, R, Php etc. But I will write the code using JavaScript and Python. 
Using python 
print("Welcome to computer Science") .
This will output Welcome to computer science
Using JavaScript,
console.log("Welcome to computer science") on your browser console but on your Html document it is written as 
document.write("Welcome to computer science")