Question

being a parent is not always easy,and being the parent of a child with special needs

a.it b.them c.one d.him
a,c解释
being a parent is not always easy,and being the parent of a child with special needs often carries with ____extra stress.

Answer 1

"it" 是做形式宾语:
(1) 答案是 A: it ("it" 代前面的 "being a parent ..." =<作为父/母的情况...>
(2) "them" 肯定错, 因为"a parent/parent" = 单数!
(3) "one" : <一个人>; 指父/母; 也是错误的. 因为句子前面的"being"不是指人(父/母), 而是指<情况>
(4) "him" 指父...也错!
(5) 改写句子你会更理解:
(i) ... and <being the parent of a child with special needs> (= it) often carries extra stress for those who are the parent of a child with special needs.
(ii)... and <being the parent of a child with special needs. (=it) often causes extra stress for that person who is the parent of a child with special needs.

Answer 2

请补充，没看懂，你的空在哪里，是选词填空吧？

从语法上说应该选one，但是从常识上说，这个空不成立，没有空才顺溜。
因为extra stress就是个名词，it又是个指代名词，两个就重复了，只能勉强填one。
最顺应该说：carries extra stresses

Answer 3

只能选择c了吧，其他的都读不通