[求助]什么叫做run-on sentence

以下是引用atongmu在2003-9-8 17:29:00的发言：
楼上的说法好像不够确切，举例如下：
135. Intar, the oldest Hispanic theater company in New York, has moved away from the Spanish classics and (now it draws on the works both of contemporary Hispanic authors who live abroad and of) those in the United States.
(A) now it draws on the works both of contemporary Hispanic authors who live abroad and of
(B) now draws on the works of contemporary Hispanic authors, both those who live abroad and those who live
(C) it draws on the works of contemporary Hispanic authors now, both those living abroad and who live
(D) draws now on the works both of contemporary Hispanic authors living abroad and who are
(E) draws on the works now of both contemporary Hispanic authors living abroad and those

这里用and连接2句句子，但也属于run-on。

以下是引用etone在2003-9-8 17:32:00的发言：

why? can someone explain it in detail? thanks a lot!!