Cho đường tròn (O) bán kính OA và đường tròn (O') đường kính OA. Vị trí tương đối của hai đường tròn là:

A. Nằm ngoài nhau

B. Cắt nhau

C. Tiếp xúc ngoài

D. Tiếp xúc trong

Choose the correct word A, B, C or D for each gap to complete the following passage:

Viet Nam is a multi- cultural country with 54 ethnic groups living together. The Viet (or Kinh) people account (1)… about 87% of the country’s population. They(2)… inhabit the low land and deltals. The other 53 ethnic minority groups (3)…. scattered over mountainous areas, from the North to the South.The ethnic groups in Viet Nam (4)…. different languages, yet they live close to each other.(5)…. they are involved in cultural exchange, they keep retaining the identity of their own culture.

Question 1:

A. at

B. in

C. for

D. about

Rút gọn

a ) 2 a 2 b 4 50 b )   2 a b 2 162   v ớ i   a ≥ 0