阅读下面文言文，按要求回答1－2题。 风烟俱净，天山共色。从流飘荡，任意东西。

It's easy to take your hearing for granted until it's too late.

With the wide    16  _ (popular) of digital entertainment products, it is not uncommon to see people wearing headphones and listening to music    17   running in the park or using public transport. And the volume is often    18  loud that people around them can hear the music as well.

However, doctors warn that such behavior can potentially damage    19__ hearing. "Innoisy places, people tend   20 _(turn) the volume up to get the same clarity of sound. Unfortunately, that can damage the hearing   21  people being aware of it," said Feng Yongfeng, chief ENT physician at Beijing Tian'an Hospital.

After Spring Festival, the hospital witnessed    22  slight increase in the number of teenagers coming in with hearing problems,    23  Feng attributed to them wearing headphones at home for long periods during the holiday. Feng said both in-ear and overhead headphones can harm the ears and    24  (advise) against using them for long periods. He said if you do use headphones it is worth  25  (invest) in the highest quality you can afford.

一艘轮船顺流航行的速度为24千米/时；逆流航行的速度为20千米/时．则水流的速度为______．

边防治安工作主要是维护边境地区的治安秩序，保护国界安全的不可侵犯性。 ( )

牵引根据动力可分为（）

A.手法牵引

B.间歇牵引

C.机械牵引

D.持续牵引

E.电动牵引

某年某月某日，某铁矿发生火灾事故，由于该矿和临矿互通，火灾共涉及5个矿区，造成上百人被困井下。经多方抢救，遇难矿工人数仍达70人。随即成立了国务院事故调查组，调查组由国家安全生产监督管理总局、监察部、全国总工会、国土资源部、省人民政府联合组成，分为综合、技术、管理三个组。国务院事故调查组经初步调查，认定事故发生的直接原因是：该矿的维修工在井筒内使用电焊，焊割下的高温金属残块及焊渣掉落在井壁用于充填护帮的荆笆上，造成长时间阴燃，最后引燃井筒周围的荆笆及木支护等可燃物，引发井下火灾。5个矿区越界开采，造成各矿井下巷道贯通，风流紊乱，火灾烟气蔓延，各矿均未按要求设置井下作业人员逃生的安全通道，直接导致了事故的升级和扩大。

生产经营单位的生产经营场所和员工宿舍未设有符合紧急疏散需要、标志明显、保持畅通的出口，或者封闭、堵塞生产经营场所或者员工宿舍出口的，（）。

A.责令限期改正

B.逾期未改正的，予以关闭

C.逾期未改正的，责令停产停业整顿

D.造成严重后果的，要依法给予赔偿，不用追究刑事责任

E.造成严重后果，构成犯罪的，依照刑法有关规定追究刑事责任