合约交割月份
参考答案：
是指某种期货合约到期交割的月份。
I can't leave. She told me that I _____ stay here until she comes back. [ ]
A. can
B. must
C. will
D. may
IgE.与过敏反应有关，其含量仅占人体免疫球蛋白总量的（）
A.不到1%
B.73%
C.8%
D.18%
