在硬岩隧道的开挖中，先行爆破周边孔，预先拉成断裂面，然后再爆中央部分的爆破方法称为（）。
参考答案：预裂爆破
读短文，判断对“√”或“×”。
Children like to watch animals. They often (经常) go to the zoo to watch animals. The monkeys are playing.
They like to eat bananas. A tiger has fur, paws, and stripes. The sheep are white. They are eating grass. The
birds have beautiful feathers. They are flying. The pandas are black and white. They like to eat bamboo (竹子).
( ) 1. Children like to watch animals.
( ) 2. Monkeys like to eat grass.
( ) 3. A sheep has fur, paws, a tail and stripes.
( ) 4. The giraffes are short.
( ) 5. The pandas are white and black.
水泥硬化包括溶解、胶化、（）三个阶段
A.凝固
B.固化
C.结晶
D.分解
