根据汉语提示或首字母填空
1．As we all know, most walls are made of concrete b________.
2．We can get a good v________ of the lake through our hotel window.
3．The climbers took cover from the storm in a c________.
4．He is not a ________(可靠的) person，for he never keeps his promise.
5．I fell asleep as soon as my head hit on the ________(枕头)．
6．At m________ you can hear the clock striking twelve.
