<img src="https://zk.995w.com/lqwvjeImg/96/96ed35de9b5593a65123c9d7a2f04965.png">自然边界条件是: ( )<br>·<img src="https://zk.995w.com/lqwvjeImg/a4/a4c256ebe664c55f4ddc610d80a88924.png"style="width:43px;height:34px;">有限<br>·<img src="https://zk.995w.com/lqwvjeImg/04/04cdfaebc8b3fb5c6b8d4aefee0547b0.png"style="width:77px;height:34px;"><br>·<img src="https://zk.995w.com/lqwvjeImg/e6/e67d6be2a82007b41187d74b594269c5.png"style="width:46px;height:34px;">有限<br>·<img src="https://zk.995w.com/lqwvjeImg/90/90d2cf167c33d53da26fa57f0d808c3b.png"style="width:76px;height:34px;">