WORKING ON MATH PROBLEM 中的 WORK为什么要加ING

WORKING ON MATH PROBLEM 中的 WORK为什么要加ING Is it working这里的work 为什么加ing. 请问：Can you work out this maths problem 为什么math要加s? there is nobody by that name working here.work为什么要加ing形式 work on the math problem是什么意思 i don't believe in working too hard .work为什么加ing We have succeeded in finish the hard work 中的finish为什么要加ing 是用动名词还是动词不定式working(to work) out the math problem like this Could you help me___out the math problem? A.working B.work C working on math ,whysics problems The maths problem is too difficult.math为什么加s like hard work.work为什么不加ing.