Chất lỏng trong eclen là chất lỏng

A. Nặng hơn chất lỏng ở phễu chiết.

B. Nhẹ hơn chất lỏng ở phễu chiết.

C. Hỗn hợp cả hai chất.

D. Dung môi.

They held a party to congratulate their son _____ his success to become an engineer.

A. in 

B. on 

C. with        

D. for

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following question from 44 to 50.

The rules of etiquette in American restaurants depend upon a number of factors the physical location of the restaurant, e.g., rural or urban; the type of restaurant, e.g., informal or formal; and certain standards that are more universal. In other words, some standards 5 of etiquette vary significantly while other standards apply almost anywhere. Learning the proper etiquette in a particular type of restaurant in a particular area may sometimes require instruction, but more commonly it simply requires sensitivity and experience. For example, while it is acceptable to read a magazine in a coffee shop, it is 10 inappropriate to do the same in a more luxurious setting. And, if you are eating in a very rustic setting it may be fine to tuck your napkin into your shirt, but if you are in a sophisticated urban restaurant this behavior would demonstrate a lack of manners. It is safe to say, however, that in virtually every restaurant it is unacceptable 15 to indiscriminately throw your food on the floor. The conclusion we can most likely draw from the above is that while the types and locations of restaurants determine etiquette appropriate to them, some rules apply to all restaurants.

Which of the following words is most similar to the meaning of “rustic” ?

A. urban

B. unsophisticated

C. agricultural

D. ancient

Xét nguyên tử Hidro theo mẫu nguyên tử Bo. Cho biết bán kính Bo r 0   =   5 , 3 . 10 - 11   m . Quỹ đạo dừng M của electron trong nguyên tử có bán kính

A. 47 , 7 . 10 - 10   m

B.  4 , 77 . 10 - 10   m

C.  1 , 59 . 10 - 11   m

D.  15 , 9 . 10 - 11   m

Trong chân không, tia hồng ngoại có bước sóng trong khoảng

A. từ vài nanomet đến 380 nm

B. từ 380 nm đến 760 nm

C. từ vài nanomet đến 760 nm

D. từ 760 nm đến vài milimet