这个数学题不容易,我没法解答.
not easy= difficult
work out 算出,解出后面还有一空，A,with out he B.with him C.without him D.with he后面还有一空，A,with out he B.with him C.without him D.with heC.without him
without him 表条件， 意即“如果没有他”， 我是做不出来的