It is so difficult a problem that _____ student in this class _____ work it out.
He never to help others in trouble because he is a kind-hearted man.
As the party was very informal, Jack stood there looking stiff and in his formal dress.
Mark have hurried. After driving at top speed, he arrived half an hour early.
He didn't make clear when and where the sports meet would be held.
Being able to speak another language fluently is a great when you are looking for a job.