When do you think ______ start the new attack?

This robot is supposed to save a lot of labor, but it remains a problem if it ______.

石墨烯是一种仅由碳原子构成的单层平状结构的新型纳米材料，具有非同寻常的导电性能，它还可以用来开发制造处超轻型飞机材料和坚韧的防弹衣。下面关于石墨烯的叙述，正确的是

The professor could hardly find sufficient grounds _____his arguments in favor of the new theory.

在社会工作研究中，定性研究方法侧重于()。