隧道衬砌工作台车上应搭设不低于（）的栏杆，跳板设防滑条，梯子应安装牢固，不得有钉子露头和突出尖角。
A.0.6m
B.0.8m
C.1.2m
参考答案：C
"_____ you've made! But you should work still harder," Dad said to me.[ ]
A. What big mistake
B. How big mistakes
C. What great progress
D. How great progress
great progress