A、<p><span style=\""font-size:14px;font-family:宋体\"">连续点<\/span><\/p>

B、<p><span style=\""font-size:14px;font-family:宋体\"">第一类间断点<\/span><\/p>

C、<p><span style=\""font-size:14px;font-family:宋体\"">第二类间断点<\/span><\/p>

D、<p><span style=\""font-size:14px;font-family:宋体\"">不能由此确定连续点或间断点<\/span><\/p>