(20~24) Dear Danny, I am a junior high school student. I have eight classes a day,   20   I am really busy with my study. I wake up at six in the morningevery day   21   I need to take a forty-minute bus ride to school.I am good at English,   22   not good at math. I listen to the teacherin class and practice a lot after school, but my math grades are stillvery bad. I do not know what to do. Please help me.                                                                                                                                                   Best,EricDear Eric,   I know how you feel because I   23   also bad at math whenI   23   a junior high school student twenty years ago. I can sharemy tips with you. First, ask teachers questions in class, not after class.In this way, teachers can know your problems right away and giveyou some help. Second, keep practicing. Third, do homework with yourfriends. You can learn from   24   . I hope these tips are useful.                                                                                                                                              Best,Danny
【題組】20.
(A) or
(B) but
(C) because
(D) so