问题
选择题
---Bear in mind that you won't be able to cancel the contract ____you've signed.
--- I _____.
A．unless; do
B．since; will
C．once; will
D．after; have
答案
答案：C
句意: ---- 要一定牢记,一旦签了合同, 你就不能撕毁它。---- 我会的。
once 意思为 “一旦；一……就”,对于祈使句的回答要用wil。