世界发达国家最集中的地区是( )
A:东南亚
B:欧洲西部
C:拉丁美洲
D:北美洲
- Do you know the boy in blue?
- Yes. I ________ him several times since last month.
如图,∠A=∠B=90°,AB=7,AD=2,BC=3,在边AB上取点P,使得△PAD与△PBC相似,则这样的P点共有( )
The rivers ____ ____ because there was little rain.
若输入a=5,b=12,则通过下列程序框图输出结果是( )