The teacher told him to come here on time,_____,he was still late.

问题描述:

The teacher told him to come here on time,_____,he was still late.
A.however B.but C.because D.so
说明理由

选A,SO表示承接,意思不对(应该是转折),其他二个都不能两头用逗号
BUt不能两头用逗号,下面的回答错误!