Điền vào chỗ trống:

a) Tiếng bắt đầu bằng

b) Tiếng có

Trong thí nghiệm giao thoa ánh sáng của I – âng. Hai khe hẹp cách nhau 1 mm, khoảng cách từ màn quan sát chứa hai khe hẹp là 1,25 m. Ánh sáng dùng trong thí nghiệm gồm hai ánh sáng đơn sắc có bước sóng λ 1  = 0,64 μm và λ 2 = 0,48 μm. Khoảng cách từ vân sáng trung tâm đến vân sáng cùng màu với nó gần nó nhất là

A. 3,6 mm.

B. 4,8 mm.

C. 2,4 mm.

D. 1,2 mm.

The death of Tran Lap, the leader of a Vietnamese famous rock band called Buc Tuong, is a great_________to his fans.

A. losing                

B. loss                              

C. lose                   

D. lost

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 25 to 29. Fill in the appropriate word in question 28

  How men first learnt to invent words is unknown; in other words, the origin of language is a (25) _______. All we really know is that men, unlike animals, somehow invented certain sounds to express thoughts and feelings, actions and things so that they could communicate with each other; and that later they agreed (26) _______ certain signs, called letters, which could be combined to represent those sounds, and which could be written down. These sounds, (27) _______ spoken or written in letters, are called words. Great writers are those who not only have great thoughts but also express these thoughts in words that appeal powerfully to our minds and emotions. This charming and telling use of words is what we call literary (28) _______. Above all, the real poet is a master of words. He can convey his meaning in words which sing like music, and which by their position and association can (29) _______ men to tears. We should, therefore, learn to choose our words carefully, or they will make our speech silly and vulgar.

A. form

B. work

C. prose

D. style

30

0.15m

1080km/h

Câu 2: Chùm song song trong mọi trường hợp

Câu 7:Vị trí 1

Câu 8: Chùm hội tụ trong mọi trường hợp

Câu 6: Gương cầu lõm có thể cho ảnh ảo hoặc ảnh thật

Đàn tranh

cột điện đó cao 3m