This is because the sound you make when you say x is ex thus using a but when you make the b sound it sounds like be.
IF I can sing well enough, I'll join the school chorus.
The IF implies that something is conditional i.e. it may happen, it may not happen (it depends on whether you can sing well enough!)
Hope this helps... :)
Answer:
A <u>Background</u><u> </u><u>Knowledge</u>
Answer: (C) tense scenes or problems that arise for the characters in a text.
Have a good day and hope I helped :D *cough got 100% cough*