练习步骤:
step1:划分句子结构,找句子主干
step2: 确定修饰词,修饰短语或修饰从句的修饰关系
step3: 确定代词指代对象
剑桥雅思9
Reading Passage 1
长难句:For instance, they were used to stain previously invisible microbes and bacteria, allowing researchers to identify such bacilli as tuberculosis, cholera, and anthrax.