“鱼儿离不开水”对此恰当的解释是 [ ]
A．生物适应环境
B．生物改变环境
C．生物依赖环境
D．生物造就环境
答案：A
—Any information about your son?
—No. If only I ________ those tough words to him.[ ]
A. didn't say
B. hadn't said
C. shouldn't have said
D. couldn't have said
人工挖孔桩从上至下逐层用镐、锹人工挖土时，挖土顺序是（）
