顶板离层指示仪达到临界值时如何处理？
参考答案：
（1）发现顶板离层达到临界值时，应立即向矿调度室汇报。由矿主管领导召集有关人员分析顶板离层的原因，并采取相应的安全技术措施。
（2）可以采取的措施主要有：
锚固范围之内离层：加大支护密度或加大支护强度。
锚固范围之外离层：安设锚索或增加锚杆长度，加固两帮，也可用金属支架加强支护。顶板离层仪的安装必须紧跟迎头，与锚杆施工同时进
| 阅读理解。 |
| In the United States, sixteen, eighteen, and twenty-one are important ages in a person's life. There are no special celebrations for these birthdays, but each is a time when a person can do new things to mark their transition (转变) into adult-hood (成人时期). After turning sixteen a person can work, get a driver's licence and leave home. Many high school students learn to drive and get part-time jobs soon after celebrating their sixteenth birthday. At the age of eighteen a person in the United States can vote and smoke, but they are prohibited from going into many nightclubs, buying wine or gambling (赌博) until they are twenty-one. In many Latin (拉丁的) cultures, a young woman's fifteenth birthday is important. At this age, she is regarded as an adult. To mark this special day, families with teenage daughters have a celebration called a Quinceanera. The day begins with the young woman and her family going to church. Later, there is a party and many guests are invited. In Japan, young people become adults at twenty. At this age, they can legally (合法的) vote, drink wine and smoke. The second Monday in January is a national holiday called Coming of Age Day. On this day, twenty-year-olds celebrate by first going to a church to pray with their families. Later, they listen to speeches given by city and school leaders. Afterward, many celebrate with family or friends late into the night. In some countries, birthday celebrations continue through adulthood. Some people celebrate their fortieth and fiftieth birthdays, or their retirement (退休) year, with a huge party. |
| 1. In the United States, age sixteen marks the time when you can ______. |
[ ] |
| A. vote and drive B. drive and get a job C. drink wine and smoke D. go into nightclubs |
| 2. In some Latin cultures, the fifteenth birthday is important for ______. |
[ ] |
| A. parents B. young men C. both young women and young men D. young women |
| 3. In Japan, young people are considered adults at age ______. |
[ ] |
| A. sixteen B. eighteen C. twenty D. twenty-one |
| 4. Which of the following is not the turning point in a person's life in the USA? |
[ ] |
| A. The 15th birthday. B. The 16th birthday. C. The 18th birthday. D. The 21st birthday. |
| 5. What is the meaning of the word "prohibit"? |
[ ] |
| A. 允许 B. 禁止 C. 终止 D. 支持 |