21. Whom_______ the bike _______?
A. does；belong to B. does; belong
C. is; belong to D. is; belong
【解析】选A。句意为：这辆自行车属于谁？belong 不能用于被动语态，只能是sth. belong (s) to sb. 。
22. In preparing scientific reports of laboratory experiments, you should _______ your finds in logical order and clear language.
A．write B．raise C．present D．rise
【解析】选C。句意为：在准备实验报告时，你应该用逻辑和清晰的语言来陈述你的实验结果。present陈述，符合句意。
