Tina _____ have known the truth, or she would have told us.

Modern science and technology has _____ communication between people far apart.

人体在晚上分泌的镇痛荷尔蒙比白天多，因此，在晚上进行外科手术的病人只需要较少的麻醉剂。既然较大量的麻醉剂对病人的风险更大，那么，如果经常在晚上做手术，手术的风险就可能降低了。下列哪项为真，最能反驳上述结论?

In recent years much more emphasis has been put______ developing the students productive skills.

北京外来务工人员比较多，大多居住在学校附近，社会工作者小唐走访部分家庭时发现，夫妻因为小孩的就学问题引起许多家庭矛盾，于是决定策划一个综合服务项目。小唐首先要做的工作应是()。