望形神的改变对诊断有重要意义,若头晕困倦,面色苍白,肢冷汗出,甚则昏不知人,多为()
A.妇科痫症
B.妇科寒症
C.妇科血症
D.妇科痛症
E.以上均不是
参考答案:C
设A={x|x2+4x=0},B={x|x2+2(a+1)x+a2-1=0},其中x∈R,如果A∩B=B,求实数a的取值范围。
Hygroscopic cargoes should be ventilated when().
A.going from a warm to a cold
B.the dew point of the outside air is greater than the dew point of the air in the hold
C.the dew point of the air in the hold is very low
D.the outside dew point is 16°C and the cargo temperature is 12°C