must怎么读,must是什么意思

as students,we must go to school ____. a.in time b.some time c.
九年级英语unit8it must belong to carla第一课时习题课件人教新目标
thinkof是什么意思
unit 5 you must come to school on time.
2018九年级英语tmustbelongtocarla第1课时习题课件新版人教新目标版