根据下面资料，回答1-20题
Decades of scientific research show that stress and anxiety are prevalent problems at work, contributing to deficits in employee morale, well-being, and productivity. 1 anxiety is caused by a range of 2 , including issues unrelated to people's jobs, one common and 3 cause is something specific to the workplace: incompetent leadership.
Managers and leaders have a 4 effect on their employees' stress and anxiety levels. 5 they say, feel, and do hugely influences their team's 6 and emotional well-being. And the more senior leaders are, the more people they are likely to influence—positively and 7 .
8 sadly, far too few leaders are aware that they have this power. And many are overconfident in their leadership skills, 9 a gap between their perceived and actual levels of 10 . This explains why even well-meaning bosses may inadvertently 11 high anxiety levels in their employees and have a 12 capacity to correct and improve their behavior： 13 you think you are leading effectively, what is the point of changing?
It is for this 14 that leaders must pay a great deal of 15 to how they act and communicate. The importance of this is exacerbated during times of increased uncertainty, 16 we often look to leaders to guide us in the face of fear, to provide us with 17 and direction, and, most of all, to give us reasons to 18 hopeful and optimistic.
If you are a manager or a leader, it is useful to 19 some key psychological lessons about how your behavior—what you say, do, feel, and express— 20 your team, especially when you are not aware of it.
第（8）题选

A Then

B But

C Thus

D Therefore