铝酸盐水泥使用蒸汽养护时，其养护温度不得高于( )。
A．30℃B．50℃C．60℃D．70℃
参考答案：B
In relation to the law of contract:
(a) discuss specific performance as a remedy for breach of contract and cite instances in which the court would refrain from granting an order for specific performance; (6 marks)
子宫脱垂的病因是（）
A.支持子宫的4对韧带过度松弛
B.慢性气管炎或习惯性便秘
C.盆底肌肉筋膜损伤
D.子宫后倾
