Ultrasound is a safe, non-invasive, FDA approved diagnostic test that USES sound waves to measure blood-flow velocity in large arteries.
超声波是FDA认可的一种安全的非侵入性诊断实验项目，利用声波来测量大动脉血管中的血液流速。
2
The shocking safety distances for blasting with various charges and safe charge for specific distance are both determined according to the particle vibration velocity safety control standard.
根据质点振速的安全控制标准，确定了不同药量爆破的震动安全距离，以及确定距离的安全药量。
3
It has advantages such as large transport capacity, high velocity, safe, punctuality, low cost, energy conservation, as well as mitigation of ground traffic jam and environment protection.