Another problem with hg is loss during sample preparation .
汞还有另外一个问题，就是在制样时候的损失。
They found the men increased their systolic blood pressure by 6 mm hg and diastolic blood pressure by about 3 mm hg .
他们发现参试者收缩压提高了6毫米汞柱，舒张压提高了3毫米汞柱。
G is in the center of g means gh = hg for any h.
g在群g的中心，意指对任意h，都有gh=hg。
Last week google put paid to speculation about the meaning of three " unexplained phenomena " doodles by admitting that they were designed to commemorate the 143rd birthday of the novelist hg wells .
