$\Rightarrow$
3. Why were you late for class yesterday? - Because I missed the first bus.
4. Why does my tooth hurt? - Because she has a cavity.
5. Why didn't they come to the meeting last night? - Because they were busy.
6. Why does she go to the doctor? - Because she has a headache.
7. Why didn't Minh say anything? - Because he was very nervous.
8. Why do we brush our teeth after meals? - Because you want to have healthy teeth.
