你是王剛(Wang Gang)，寫一封給朋友李明(Li Ming)的祝賀信，祝賀他獲得復旦大學計算機科學碩士學位，并祝他今后在學習和研究方面取得成功。

Rescue dogs are chosen probably because__

• A、they are loyal 

• B、they are brave

• C、they have amazing appearances

• D、they have good eyesight

Moviegoers know that many special effects are created by computers, __ they often don't know is that these scenes still require a lot of work.

• A、That

• B、Whom

• C、What

• D、How