---When will the expert e and give the lecture on economic development?
---Not until our program .
A. is approving
B. is to approve
C. has been approved
D. will be approved
网友回答
A. is approving
B. is to approve
(答案→)C. has been approved
D. will be approved
解析：句意：--什么时候专家会来给我们做关于经济发展的讲座？--直到我们的项目被批准。这里是not until引导的时间状语从句，不能用一般将来时，可以用一般现在时代替一般将来时，或现在完成时代替将来完成式，而且program和approve是被动关系，选C。