The availability of the appropriate compiler guarantees that a program developed on one type of machine can be compiled on a different type of machine.
true / false.

This is probably false. Take a language like C++, and even though some open source compilers will work for both Windows AND Linux, some functions or libraries may be available on Windows but not Linux and vice versa. Theoretically, if you're using the standard library and the compiler supports it, then yes, but in practice, the answer is usually no.

yes you can very simple, click the heart and then click the follow requests button.

i think the answer is a or d