当选用路堤填料时用硬质岩石及不易风化的软质完的碎石时，应级配较好，块石类填料的粒径不得大于（）。
A.20cm
B.15cm
C.25cm
参考答案：B
The storm left, _____ a lot of damage to this area.
[ ]
A. caused
B. to have caused
C. to cause
D. having caused
一只猫吃一只老鼠，用5分钟吃完；5只猫同时吃5只同样大小的老鼠，要几分钟吃完？
