In context, what is the best way to deal with sentence (3)?
Directions for the question:
The following passage is an early draft of an essay. Some parts of the passage need to be rewritten.
Read the passage and select the best answer for the question that follows. Keep in mind that some questions are about particular sentences or parts of sentences and ask you to improve sentence structure or word choice. Other questions ask to consider organization and development. In choosing answer, follow the requirements of standard written English.
(1) Research in education has of recent years turned its attention to the problem of assessing a student’s progress as accurately as possible. (2) Only when this is done, can a meaningful course of study be laid down and a student helped to recognize his difficulties and overcome it. (3) But, despite all the new thinking on this subject, there is still no acceptable alternative to the examination. (4) There have been remarkable advances in analyzing the process of learning and in framing tests and maintaining week to week records which provide the teacher with valuable information about the progress of his class and of each individual in it. (5) Whether it be at the end of term, or the year, or at the end of a school course or for the purpose of choosing candidates for a course of study and training, the only practicable way of measuring a student’s performance or of assessing his potential is by an examination, supplemented where necessary, by recommendation, interview and other devices.