BECAUSE DIEN BIEN PHU IS ONLY 30 KILOMETERS FROM LAOS BORDER.

4. - DAP AN DE DU BI HSG BAC GIANG 09 10
Lớp 9 Tiếng Anh DAP AN DE DU BI HSG BAC GIANG 09 10

4. Because Dien Bien Phu is only 30 kilometers from Laos border.