中暑痉挛区别于其他各型中暑的主要特征是
A．头痛
B．恶心、呕吐
C．惊厥
D．阵发性肌肉痉挛疼痛
E．全身疲乏
参考答案：D
已知菱形的两条对角线长分别是6和8，则这个菱形的面积为（ ）．
The number of people invited __________ fifty, but a number of them __________ absent for different reasons
A．were ; was
B．was ; was
C．was ; were
D．were ; were
