问题补充：
Only when the painting decide whether the painting is worth buying.
A. he sees, he can
B. does he see, can he
C. he sees, can he
D. sees he, he can
答案：
A. he sees, he can
B. does he see, can he
(答案→)C. he sees, can he
D. sees he, he can
解析： only引导的状语在句首，主句要部分倒装。
