用正确的数字和符号填空：
(1)2个氯原子______；
(2)保持氧气化学性质的微粒____。
(1)2Cl
(2)O2
记账凭证既是记录经济发生和完成情况的书面说明，也是登记账簿的依据。
It is not how much we do but how much love we put into what we do ______ benefits our work most. [ ]
A. who
B. which
C. that
D. what
