【单选题】哪一项现场试验无须在钻孔中完成? ( )
【单选题】低温生物学认为,在负196度的()中,生命体可以长久保存。
【判断题】安史之乱是海上丝绸之路开始衰落的标志性事件。
【简答题】He (lead) a group of students to meet the professor last month.
【多选题】按采购政策分类 , 可以将采购分为( )
【简答题】He wants to lead a life of _______.(virtuous)
【单选题】Sam felt he had nothing to the discussion, so he left early.