A、<p> <span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px">不变，降低</span></p>
B、<p> <span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px">降低，不变</span></p>
C、<p> <span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px">不变，不变</span></p>
D、<p> <span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px">降低，升高</span></p>