Parts of the given sentence have been given as options. One of them may contain an error. Select the part that contains the error from the given options. If you don't find any error, mark 'No error' as your answer. Southern states has made an impressive comeback in the latest rankings.

The following sentence has been divided into parts. One of them may contain an error. Select the part that contains the error from the given options. If you don't find any error, mark 'No error' as your answer. Marine vertebrates are / valuable for / many reasons.

The following sentence has been split into four segments. Identify the segment that contains a grammatical error. To descend a cragged / mountain, however, was most / difficult and dangerous / than to ascend it.