ocr: the "//"is used for one-line comments. You can still use the "/*" - and "*/" for multi-line comments. endi - refers to a newline character. Similar to the "in" control character. Note that "In" can still be used. Ok, now let's begin ! To print the number 55, use mainU I cout << 55 << endl; // prints the number 55 I The classic 'hello, world!" would be: mainUl cout << "hello, world!" << endi; ; )