pp中: The [surface of] Venus is obscured [by the] planet's thick clouds [yet] so is invisible [to] optical instruments. 答案: c c是不太顺眼,但不太清楚怎么改,直接去掉么(yet可以连接句子的呀)? 但感觉so之后应该加it 另外, Venus之前不需要加 the么? Sun, moon, earth之前都加的呀,不是独一无二的东西要加the吗? 而且同样是pp中之前一道题就是Light from the Sun... 各位给点意见吧!