表示选择关系的并列句
常用的连词有or , either…or…..，otherwise, or else(否则）, 等连接.如：
Either you are mad or I am. You must go early, otherwise you will miss the bus.
Will he still be there or will he have gone away? Take this bus or else you won’t get there in time.
第五种句型：S+V+P
She is a student. He has become an engineer.
It tastes sweet.
His face goes red.
注意：系动词除了be 动词外，还包括become, turn, look, seem, appear, sound, taste, smell, remain, prove, keep, fall.
并列句：由并列连词把两个或两个以上的简单句 连在一起的句子叫做并列句。
He helps me and I help him. He not only gave us a lot of advice , but also helped us to study English.
注意：不同的并列连词表示并列分句之间的不同关系， 根据并列分句之间的关系不同，并列分句可以分为四种。
Once, she teached in India for many years . In 1950, she set up the Missionaries of charity to help the poor in Calcutta. She devoted to help the poor 、 the patiences、the homeless persons and the dead persons. Because of those, in 1979, she got the Nobel peace prize in 1997. she died in India.
