In medical Doppler ultrasound systems, a high-pass filter is usually employed to remove wall clutter components which may also remove the information of the low velocity blood flow.
医学超声多普勒系统的高通滤波器在消除血管壁搏动带来的回波干扰时，也滤除了低速血流信息。
2
High winds can get under the frisbee and change its direction, making it difficult for team members to pass.
大风可以压低飞盘，改变其方向，使得队员难以传递。
3
For instance, highway overpasses had to be high enough to allow trailers carrying military missiles to pass under them.