<正> 病句一:He bought a farm near a stream but which istoo hilly to be irrigated. but which 引导的从句只能跟在同类型的或者修饰同一事物的从句之后,因为but是等立连词。此句可把介词短语改成从句,Hebought a farm which is near a stream but is too hilly…。 (他买下一个农场,农场靠近溪流,但是太陡了无法灌溉。) 病句二:He is a boy whom I am sure can be trusted. 句中使用whom是错的。由于插入I am sure,使从句的关系