非典疫情蔓延，集中暴露出我国( )发展不协调的问题。
A．区域
B．经济和社会
C．城乡
D．人与自然
参考答案：B
植物根吸收的水分在植物体内运输的途径是
A．导管
B．筛管
C．气孔
D．根毛细胞
—What’s wrong with you yesterday?
—When I was playing football, my strength ___________ and I fell down.
A．gave up
B．gave off
C．gave out
D．gave in
