根据短文理解，从A、B、C、D四个选项中选择正确答案填空。
“It's raining cats and dogs!” Grandpa shouted.
Little Richie came running to the window. He wanted to see the 1 falling from the sky. He looked out of the window, but it was 2 that there were no cats or dogs. He only saw small pools of water on the ground.
“Man, it's really coming down out there!” Uncle Bob agreed 3 he looked out of the window, too. Richie scratched his head(挠头). What was coming down? First they talked about cats and dogs that 4 be seen. Now someone said “it”. What was going on with these 5?
“Wow!” Aunt Susie shouted as she looked out of the window. “It's raining really hard.”
Richie 6 his aunt. “It's raining hard,” he agreed, “but 7 are the cats and dogs?”
Grandpa laughed. “ Richie, that just 8 it's raining really hard.”
“So why didn't you just say that?” Richie 9. It was irritating(恼人的) when people spoke like they were not speaking English at all.
“We did. You just didn't understand these 10.” Richie's cousin said with a big smile.
“Well, now I do.” Richie said.