vd:nam châm điện, dòng điện đi qua nó làm cho nó hút sắt, đó là tác dụng từ

nồi cơm điện, dongf điện đi qua nó làm cho nó nóng lên nấu thành cơm, đó là tác dụng nhiệt

5 a) do đoạn mạch song song nên:

A1+A2=A

suy ra :A2=A-A1

hay A2=0.6A-0.2A

A2=0.4A

b) do đoạn mạch song song nên

U=U1=U2

lại có U=3V

suy ra U=U1=U2=3v

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.

In many countries of Northern Europe, including Scandinavia, Finland, Northern Russia, and the Baltic states, ice swimming is closely connected with the tradition of sauna, (25)______ has led to the creation of a new activity where stays in the sauna are (26)______ with quick 'pauses' in ice water. In Russia, ice swimmers are called what can be literally translated as 'walruses '. The north of Europe, (27) ______, is not the only place where winter swimming is practised regularly. A large ice swimming movement exists in the UK, based in a famous location: the Serpentine Lake in Hyde Park in London. In Harbin, Northern China, about 200,000 people ice-swim in the Songhua River every winter. The oldest ice swimming club in the United States, the Coney Island Polar Bear Club of New York, organises an annual (28) ______ on New Year's Day. In Canada, 'Polar Bear Swims; 'Plunges' or 'Dips' are a New Year's Day tradition in (29)______ communities as well, the biggest one taking place in Vancouver since 1920.

Điền vào ô trống 29

A. numbering 

B. numerate 

C. numerable 

D. numerous