1. The underload on the power grid caused the voltage to drop, leading to frequent power outages.
电网的负荷不足导致电压下降，频繁发生断电的情况。

2. Students often feel stressed when they have an underload of course work because they worry about falling behind their classmates.
学生们在课程负荷不足时常常感到压力，因为他们担心会落后于同学们。