Chất nào dưới đây chứa ion đa nguyên tử?

A. C a C l 2 .       

B.  N H 4 C l .       

C.  A l C l 3 .       

D. HCl.  

Thành tựu nào khoa học nào của nhân loại đã bị biến thành vũ khí hủy diệt trong chiến tranh thế giới thứ hai?

A. Tàu ngầm U-boat 

B. Bom nguyên tử

C. Máy bay ném bom 

D. Pháo phản lực Katyusha

Căn cứ vào Atlat Địa lí Việt Nam trang 19, cho biết tỉnh nào sau đây có diện tích trồng lúa nhiều hơn cả?

A. Thái Bình.

B. Hải Dương.

C. An Giang.

D. Hậu Giang.

Hãy xác định những thông tin sau là Đúng (True) hay Sai (False).

The school year in Vietnam runs from September through the first of June. It is divided into two semesters. The first semester begins in September and ends before the Lunar New Year, while the second one begins right after the first one and lasts until June the first. Children in Vietnam go to school six days a week from Monday to Saturday and a typical school day runs from 7:00 to about 11:30 in the morning. Vietnamese students are expected to take school very seriously and to work hard. Most periods begin with a small test. The teacher calls on some students to stand and answer a few questions to check their understanding of the last lesson.

After school, Vietnamese students take part in a lot of activities. Some students play sports. Soccer, table tennis, and badminton are the most popular. Others enjoy going swimming. A few students like music and movies. They often practice playing musical instruments in the music hall or go to the cinema with their friends to see the latest films. In addition, some students play video games or computer games or stay at home to help their parents. The after-school activities above help students find friends with similar interests, develop their talents, and sometimes even discover their career goals.

The teacher often tests the students’ knowledge of the last lesson before starting new lessons.

A. True

B. False