将左边和右边的句子连成对话。
①Moo ...Moo ...What do you hear? ____ A. Yes, I can.
②Listen! What can you hear?____ B. I hear a cow.
③Can you hear some dogs?____ C. It's a train.
④What is it?____ D. I can hear a ship.
读南方地区“珠江三角洲简略图”完成下列各题。
解方程:x2+2x﹣1=0.