Its just that some words outweighs another and while you can say that when is a support you really need the line after that (which points toward a specific thing) to solve the blank . So, even if you neglect when in the blank , you can still guess the correct answer while focusing on the word that .
I am attaching a very cool support contrast list made by one of our member which can help you :
Hey,
1.does semicolon in the sentence mean support in the math strategy?
2.Also if you could give what other punctuation show/stand for?
3. Is there a way to think about it and find out?