填空题 The elements can be classified broadly into three basic groupings，i.e.：A）（），metalloids，and B）（）because they have certain common properties.

单项选择题 The head of the Los Angeles police department said those without tickets ______ to take part in it in the area. A．will not be allowed B．dont allowed C．are not allowed D．wouldnt be allowed

多项选择题 里程碑计划的编制步骤包括（）。