虚劳腰痛，少腹拘急，小便不利者，_______主之。
参考答案：肾气丸
光的速度是每秒3×105千米，太阳光照射到地球上大约需要5×102秒，计算地球与太阳的距离大约是多少？
In the US they focus on creative thinking skills, ________ in China they only focus on theory.[ ]
A. since
B. when
C. while
D. now that
