After four years’ research, we now have a ______ better understanding of the disease.

Such a problem is＿＿＿＿difficult for a primary school student ＿＿＿. 

I don’t like her face;        , she smokes, which is something I hate.

—Hi, I hear you’re going to London this summer vacation. —            , I was going to, but now I have changed my plan.

I have little doubt about his competence; ______, he is well-qualified for the job.