1. Ta nhan bik dc anh sang khi nao? Cho vi du
2.Ta nhin thay mot vat khi nao? Cho vi du
3. The nao la nguon sang? Vat sang? Vat dc chieu sang?
4. Khi nao xay ra hien tuong nhat thuc, nguyet thuc?
5. Hien tuong phan xa anh sang la gi?
6. Phat bieu dinh luat phan xa anh sang?
7. So sanh anh cua mot vat ao boi guong phang, guong cau loi va guong cau lom co diem gi giong nhau va khac nhau?
8. Phat bieu dinh luat thang anh sang
9. The nao la chum sang song song, chum sang hoi tu va chum sang phan ki?