—They didn’t go swimming yesterday, did they?

—_______ I saw them skate in the park.[ ]

A. Yes, they did.

B. No, they didn’t.

C. Yes, they were.

D. No, they weren’t.

关于显影的叙述，错误的是

A．全部为化学显影
B．显影途径分物理显影和化学显影
C．物理显影与化学显影原理是一样的
D．将潜影转换成可见银影的化学反应过程
E．化学显影把乳剂中的Ag⁺作为还原银的来源