引起原发性非典型肺炎的支原体主要是（ ）
A．肺炎支原体
B．解脲脲原体
C．人型支原体
D．生殖道支原体
E．发酵支原体
参考答案：A
35. Many people agree that never in history a more splendid opening ceremony than that of the Beijing Olympics.
A．there were
B．has there been
C．there has been
D．were there
被撤销的民事行为从撤销时开始无效。 ( )
