医生通过超声波检查心脏结构。

The doctor used an ___ultrasound to examine the heart's structure.

医生建议她做超声波检查以查看肝脏情况。

The doctor recommended an ___ultrasound to examine her liver condition.

医生用超声波检查孕妇的胎儿。

Doctors use ___ultrasound to examine a pregnant woman's baby.