下述哪一种示功图能用来计算柴油机的功率（）
A、P—V转角示功图
B、梳形示功图
C、弱弹簧示功图
D、P—V示功图
参考答案：D
In relation to the law of contract:
(b) explain and distinguish between the following terms:(i) executory consideration; (2 marks)(ii) executed consideration; (2 marks)(iii) past consideration. (3 marks)
哮证发作时的病理关键在于（）
A.痰阻气闭
B.肺失宣降
C.伏痰
D.肺气不清
E.肺气虚寒
