设函数<img src="/lqwvjeImg/40/408e29de7864e72d3bbc45e460558c84.png"style="width:31px;height:19px;">在点<img src="/lqwvjeImg/34/341b06577ae7aa0ae906d6e6a13005c6.png"style="width:15px;height:13px;">不可导,则( )<br>·<img src="/lqwvjeImg/40/408e29de7864e72d3bbc45e460558c84.png"style="width:31px;height:19px;">在点<img src="/lqwvjeImg/34/341b06577ae7aa0ae906d6e6a13005c6.png"style="width:15px;height:13px;">没有切线<br>·<img src="/lqwvjeImg/40/408e29de7864e72d3bbc45e460558c84.png"style="width:31px;height:19px;">在点<img src="/lqwvjeImg/34/341b06577ae7aa0ae906d6e6a13005c6.png"style="width:15px;height:13px;">有铅直切线<br>·<img src="/lqwvjeImg/40/408e29de7864e72d3bbc45e460558c84.png"style="width:31px;height:19px;">在点<img src="/lqwvjeImg/34/341b06577ae7aa0ae906d6e6a13005c6.png"style="width:15px;height:13px;">有水平切线<br>·有无切线不一定