急性肺梗死主要引起（）
A.左心室容量负荷过重
B.左心室压力负荷过重
C.右心室容量负荷过重
D.右心室压力负荷过重
E.心肌代谢障碍
参考答案：D
乐音的三个特征是音调、 和音色。我们能够听到蜜蜂飞的声音，却听不到蝴蝶飞的声音，主要原因是它们飞行时发出声音的 不同。
By using new foreign textbooks, we could not only learn the right expression of business ideas, but also we will know the lastest developments in the business world.
A．but also will know the lastest
B．but also know the lastest
C．but also know the latest
D．but also come to know the latest
