Cuộc cách mạng khoa học – kĩ thuật lần thứ hai khởi đầu từ quốc gia nào?

A. Anh.

B. Pháp.

C. Liên Xô.

D. Mỹ.

Sóng ra khỏi khối trộn sóng là:

A. Sóng cao tần

B. Sóng trung tần

C. Sóng âm tần

D. Có thể là sóng cao tần, âm tần, trung tần tùy thuộc từng thiết bị.

Hãy viết các biểu thức toán học sau sang dạng tương ứng trong Pascal:

D. 30

 Cho  log 3 x = 3 log 3 2 + log 9 25 - log 3 3 . Khi đó giá trị của x là :

A.  200 3

B. 40 9

C. 20 3

D. 25 9

Rearrange the words to make a meaningful sentence

at/ English/ Mary/ and/ is/ Math/ good.

Read the passage below and decide whether the statements are TRUE or FALSE?

The Hopi live in the northwestern part of Arizona in the United States. With modern things all around them, the Hopi keep their traditions.

There are about 10,000 Hopi and they live in twelve villages in the desert. The weather is very hot in summer, but in winter it freezes. The wind blows hard. Farming is difficult. Corn is the Hopi's main food, but they plant vegetables, too. They raise sheep, goats, and cattle. They also eat hamburgers, ice cream and drink soft drinks. They live in traditional stone houses, but many of them have the telephones, radios, and television. They have horses, but they have trucks too.

Kachinas are an important part of the Hopi religion. Kachinas are spirits of dead people, of rocks, plants, and animals, and of the stars. Men dress as kachinas and do religious dances. People also some make wooden kachinas. No two wooden kachinas are ever alike.

The children attend school, and they also learn the Hopi language, dances, and stories. The Hopi want a comfortable, modern life, but they don't want to lose their traditions.

Question: They live in house made of stone.

A. True

B. False

Chọn từ khác loại.

A. second

B. thirteen

C. eight

D. twelve

Cho 4,4g hỗn hợp 2 kim loại nhóm IIA thuộc hai chu kỳ liên tiếp với dung dịch HCl dư cho 3,36 lít khí (đktc). Hai kim loại là

A. Ca, Sr.       

B. Be, Mg.

C. Mg, Ca.       

D. Sr, Ba.