问题 单项选择题

关于巷道锚喷支护的说法,错误的是()。

A.锚杆长度不得小于2m,锚固力不得低于100kN

B.喷射混凝土支护厚度不低于50mm,混凝土强度等级不低于C15

C.在松软破碎的岩层中可采用超前锚杆进行预先护顶

D.在动压巷道中,宜采用锚喷网联合支护

答案

参考答案:A

解析:锚喷支护是锚杆支护和喷射混凝土支护,必要时还加设金属网进行联合支护的合称。根据《锚杆喷混凝土支护技术规范》,喷混凝土的设计强度等级不应低于Cl5;对于竖井及重要隧洞和斜井工程,喷混凝土的设计强度等级不应低于C20;喷混凝土的1d期龄的抗压强度不应低于5MPa。钢纤维喷射混凝土的设计强度等级不应低于C20,其抗拉强度不应低于2MPa。喷射混凝土的支护厚度,最小不应低于50ram,最大不应超过200mm。答案A不符合巷道喷锚支护的要求,其余选项均符合要求。

阅读理解

阅读理解。

Luggage 

     We ask you to keep what you bring with you down to one medium-sized suitcase per person on board

the bus.

Seat Arrangements (安排)

     Special needs for particular seats can be made on most bus breaks when booking, but since arrangements

are made on a first-come-first-served basis, early booking is advisable. When bookings are made with us,

you will be offered the best seats we have on the bus at that time.

Travel Documents 

     When you have paid your deposit (订金), we will send you all the necessary documents, so that you

receive them in good time before the bus break departure (出发) date. Certain documents, for example air

or boat tickets, may have to be kept and your driver or guide will then give them to you at the proper time.

Special Diets

     If you need a special diet, you must tell us at the time of booking and provide us with a copy of the diet.

This will be passed on to the hotel or hotels on your bus break. However, on certain bus breaks, the hotels

used are tourist class and they may not be able to prepare special diets. Any extra costs must be paid to the

hotel yourself before leaving the hotel.

Programs

     Some of our hotels arrange extra programs which include music, dancing and film shows, etc. They are

all offered by the hotel, but not guaranteed (保证).

1. If you want to sit in the front of the bus, you'd better ______. [ ]

A. say it when you get on the bus

B. arrive early on the departure date

C. book your seat ahead of time

D. avoid traveling at busy times

2. Your air tickets ______. [ ]

A. will be sent to you at your departure point

B. will be kept by yourself

C. will be given to you with other documents

D. may be held by your bus driver until you need them

3. If you need a special diet, you should ______. [ ]

A. tell the bus company when booking

B. pay extra money

C. tell the hotel when you arrive

D. book a tourist class hotel

4. Extra programs are ______. [ ]

A. offered by the hotel at any time

B. offered by the hotel, but may not run

C. offered by the bus company

D. an extra offer, so extra money must be paid

单项选择题