Many smokers believe that e-cigarettes can help them quit smoking. _____________, scientific researches show that e-cigarettes are more addictive and lethal than traditional cigarettes.
A. In addition
B. However
C. As a consequence
D. Equally important
Scientific researches indicate a number of negative impacts of poor sleeping quality. _____________, the problem can lead to anxiety and depression.
A. Otherwise
B. For example
C. To conclude
D. Nevertheless