多项选择题 Regarding DHCP (dynamic host configuration protocol), which two of the following choices below are true?（）

多项选择题 A legacy network that is prone to errors may have issues with services that use UDP. Which of the following services could have problems in this case, due to the fact that UDP is used?（）

单项选择题 The corporate head office of TestKing has a teleconferencing system that uses VOIP (voice over IP) technology. This system uses UDP as the transport for the data transmissions. If these UDP datagrams arrive at their destination out of sequence,what will happen?（）