Cao Lang province was merged from which localities?

A
Bac Kan and Cao Bang
B
Bac Kan and Lang Son
C
Cao Bang and Lang Son
Cao Lang is the name of the old province, based on the merger of Cao Bang and Lang Son, from December 1975. At that time, Cao Lang province had 20 administrative units including: 2 towns Cao Bang, Lang Son and 18 districts: Bac Son, Bao Lac, Binh Gia, Cao Loc, Chi Lang, Ha Quang, Hoa An, Huu Lung, Loc Binh, Nguyen Binh, Quang Hoa, Thach An, Thong Nong, Tra Linh, Trang Dinh, Trung Khanh, Van Lang, Van Quan.
The provincial capital is located in Cao Bang town. The population of the province in 1976 was nearly 900,000 people with an area of over 13,000 km2.
D
Bac Giang and Cao Bang

A
1978
On December 29, 1978, the 4th session of the 6th National Assembly passed a resolution to divide Cao Lang province to re-establish Cao Bang province and Lang Son province. In the same year, the two districts of Ngan Son and Cho Ra (now Ba Be and Pac Nam districts) of Bac Thai province were transferred to Cao Bang province for management (since 1996, these two districts have returned to Bac Kan province) and Dinh Lap district of Quang Ninh province was transferred to Lang Son province for management: Cao Bang province includes Cao Bang town and 11 districts: Bao Lac, Cho Ra, Ha Quang, Hoa An, Ngan Son, Nguyen Binh, Quang Hoa, Thach An, Thong Nong, Tra Linh, Trung Khanh.
Lang Son province includes: Lang Son town and 10 districts: Bac Son, Binh Gia, Cao Loc, Chi Lang, Dinh Lap, Huu Lung, Loc Binh, Trang Dinh, Van Lang, Van Quan.
B
1988
C
1999
D
2000

A
3
B
4
C
5
D
6
Cao Bang is a mountainous border province, located in the Northeast of Vietnam, with an important position in terms of economy, politics, and national defense for the whole country. To the west, it borders Ha Giang and Tuyen Quang provinces. To the south, it borders Bac Kan and Lang Son provinces. To the north and east, it borders the Guangxi Zhuang Autonomous Region (China) with a border of 333.125 km.

A
Bang River
B
Ky Cung River
Ky Cung is the main river of Lang Son province, originating from the mountainous area of Bac Xa commune at an altitude of 1,166 m in Dinh Lap district. The river flows from Dinh Lap through many districts of Lang Son, Cao Bang, and across the border to China. The neighboring country calls this river Binh Nhi Ha.
The section flowing through Vietnam is about 243 km long, with a basin area of 6,660 km². This is the only river in our country that flows into China.
C
Gam River
D
Lo River

A
Pogour
B
Dambri
C
Dray Nur
D
Ban Gioc
Located on the Vietnam - China border, Ban Gioc waterfall is known as one of the most beautiful waterfalls in Vietnam, the largest natural waterfall in Southeast Asia. Ban Gioc waterfall is over 60m high with the longest slope of 30m. It is divided into many successive limestone layers and spreads out to hundreds of meters. In the middle of the waterfall is a large mound of land covered with many green trees, dividing the river into three different branches.