深孔台阶爆破的超深，在岩石松软和坚硬是分别取（）值。
A.小、大
B.大、小
C.一样
D.大、大
参考答案：A
---You’d better read more English magazines to improve your reading.
---______________
A Why don’t you read it? B That’s a good idea.
C Can I help you? D I’m sorry to hear that.
我国大豆的主产区有哪四个地区？
