The pupil always dallies over difficult math problems.这个学生做数学难题总是慢慢吞吞。The class was struggling to find the solution to a maths problem.全班同学正绞尽脑汁解答一道数学难题。Give Tom a mathematical puzzle and he'll just keep on trying till he cracks it.给汤姆一道数学难题，他就会一直解下去，直到解出来为止。