机械性肠梗阻的临床表现有（）
A.腹痛、腹胀
B.肠蠕动波
C.反跳痛
D.肠鸣音亢进
E.板状腹
参考答案：A, B, D
小题1:We must learn and help _________ __________( 互相 ).
小题2:The shop sells (出售) many school things, _____ _____ ( 例如 )pens, pencils，rulers, erasers and so on.
小题3:She ________ _________ ( 有空 ) on Saturdays.
小题4:Mrs. Smith likes _________ some ________( 购物 ) on Sunday morning.
小题5:Li Lei _____ _____( 不得不) go to school on foot today because his bike is broken.
假如没有摩擦力，试写出三个合理的场景．
