试说明椭圆的画法。
参考答案:
画椭圆时,先画椭圆长短轴,定出长短轴顶点,过四个顶点画矩形,然后作椭圆与矩形相切,或者利用其与菱形相切的特点画椭圆。
早期妊娠的确诊依据是()。
A.黑加征
B.停经史
C.早孕反应
D.B超检查
E.尿妊娠试验
Describe the different classes of ‘workmen’ as stated under the West Pakistan Industrial and Commercial Employment (Standing Orders) Ordinance, 1968. (10 marks)