Trên đường thẳng xy lấy một điểm O. Vẽ các tia Om, On, Ot sao cho $ \widehat{xOm}={{40}^{0}};\widehat{yOn}={{50}^{0}};\widehat{xOt}=\widehat{yOt}. $ Trên hình vẽ có bao nhiêu cặp góc phụ nhau?
A.4 cặp góc.
B.5 cặp góc.
C.3 cặp góc.
D.2 cặp góc.

Trên đường thẳng xy lấy một điểm O. Vẽ tia Oz sao cho $ \widehat{xOz}=\dfrac{2}{3}\widehat{yOz}. $ Giá trị  $ \widehat{yOz}-\widehat{xOz}$ bằng
A.$ \widehat{yOz}-\widehat{xOz}={{72}^{0}}. $
B.$ \widehat{yOz}-\widehat{xOz}={{24}^{0}}. $
C.$ \widehat{yOz}-\widehat{xOz}={{45}^{0}}. $
D.$ \widehat{yOz}-\widehat{xOz}={{36}^{0}}. $

Choose the answer among A, B, C, D to complete each of the sentences below:
They started a campaign to...... smoking among teenagers.
A.prohibit
B.discourage
C.encourage
D.decrease

Choose the answer among A, B, C, D to complete each of the sentences below:
Recently the Asian Games has increased in ______.
A.popularity
B.polular
C.popularizing
D.popularly

Trên tia Ox lấy ba điểm A, B, C sao cho $ OA < OB < OC $ . Từ một điểm M ở ngoài đường thẳng chứa Ox vẽ các tia MO, MA, MB, MC. Giả sử $ \widehat{OMC}={{120}^{0}};\widehat{OMA}={{30}^{0}};\widehat{AMB}={{50}^{0}}. $ Tính số đo góc BMC.
A.$ \widehat{BMC}={{70}^{0}}. $
B.$ \widehat{BMC}={{50}^{0}}. $
C.$ \widehat{BMC}={{60}^{0}}. $
D.$ \widehat{BMC}={{40}^{0}}. $

Choose the answer among A, B, C, D to complete each of the sentences below:
Man has witnessed a great many significant ______ of science and technology in the past few decades.
A.achievements
B.achieved
C.achieves
D.achievers

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
Your friendship should be based on ________ trust.
A.blind
B.fragile
C.basic
D.mutual

Choose the answer among A, B, C, D to complete each of the sentences below:
The world’s coal _______ should last longer but, once used, these cannot be renewed.
A.reserves
B.stores
C.storage
D.reservations

Choose the answer among A, B, C, D to complete each of the sentences below:
We live in an age of rapid scientific and technological _____.
A.advancement
B.advancing
C.advance
D.advances

Choose the answer among A, B, C, D to complete each of the sentences below:
I've got lots of ________, but only a few are really good friends
A.close friends
B.partners
C.neighbors
D.acquaintances