单词	半值层计
释义	半值层计meter， half-value layer半值层计half-value layer meter
随便看	at that self moment at that time at that time, at the time that at that (或this) rate at the age of at the age of 14 the catamenia appear at the age of 14 the catamenia appears at the appointed tide at the appointed time at the back at the back of at the back of ... at the back of one's mind at the back of someone's mind at the bar at the bare idea of at the bare thought of at the beck (and call) of someone 或 at someone's beck and call at the beck and call of someone 或 at someone's beck and call at the beck of someone 或 at someone's beck and call at the beginning at the beginning of at the beginning of the world at the beginning of the world (celt) at the behest of