English Punctuation: !? How to Use Interrobang and Interabang

In this video, Alisha answers 5 questions. - Could you please tell me the use of these types of marks ?!, !? ,!!??, ??!! Could you give some examples? - Hi, I have two questions: First, what's the difference between "replace with" and "replace by"? My second question is question is about the use of the plural form. - "Transistors proved vital in creating the practical lasers." If I wanna translate the verb "proved" here, would it be correct to understand it as meaning "tested"? Or are there other possibilities? - What's the difference between sentences to get yourself killed and to kill yourself? - Could you please tell me the difference between suppose to and supposed to and their pronunciation while speaking? Do we have to use the ed sound while saying "supposed to" in sentences?