肛门周围局部从持续性胀痛而逐渐加重为显著跳痛，合并排尿困难，里急后重，排便时加重，伴有全身乏力、发热、不思饮食

A．低位肠梗阻
B．急性完全性肠梗阻
C．麻痹性肠梗阻
D．绞窄性肠梗阻
E．动力性肠梗阻

China ______ a lot of people moving to urban areas in the last 20 years. However, many migrants  left their families behind.

A．saw

B．sees

C．has seen

D．had seen