Although the first pulsar, or rapidly spinning collapsed star, to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, it had not been announced until February, 1968.

(A) Although the first pulsar, or rapidly spinning collapsed star, to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, it had not been announced until February, 1968.

(B) Although not announced until February, 1968, in the summer of 1967 graduate student Jocelyn Bell observed the first pulsar, or rapidly spinning collapsed star, to be sighted.

(C) Although observed by graduate student Jocelyn Bell in the summer of 1967, the discovery of the first sighted pulsar, or rapidly spinning collapsed star, had not been announced before February, 1968.

(D) The first pulsar, or rapidly spinning collapsed star, to be sighted was observed in the summer of 1967 by graduate student Jocelyn Bell, but the discovery was not announced until February, 1968.

(E) The first sighted pulsar, or rapidly spinning collapsed star, was not announced until February, 1968, while it was observed in the summer of 1967 by graduate student Jocelyn Bell.

答案是d。

感觉这题只能用排除法。

但是d选项我有一点想不通，to be sighted  在这里是什么意思。 按照sight的意思来说，它根observe是重复的。

我用这里理由，排除了d的

是的。

不过我的一个缺点就是，用一个理由排除掉几个选项后，就不会再看它们，然后对剩下的2个选项就采用非常宽松的标准。尤其是长句子，是我的超级弱项。唉

sight这个动词在这里是“（用仪器）观测（星等）”的意思

observe是“观察”的意思

很相近，是观测和观察间的细微区别？即使意思重复，其他选项是完全错了，也只好选它

意思有点重复并不是肯定错误的啦

我也觉得有问题,一开始就因为TO BE SIGHTED 排除了D,看到答案巨郁闷~

to be sighted 应该是修饰the first pulsar. or rapidly spinning collapsed star 只是插入语。

was observed 是首句的谓语。

不知道我的理解对不对啊，欢迎批判~