1. Exercise 9

2. No.1
(Worse) A comparison is made of the advantages and disadvantages of the methods in this study so that an appropriate one can be selected.
(Better) This study compares the advantages and disadvantages of the methods to select an appropriate one.

3. [Note 3.9]
Turning the subject into a verb and switching two passive voice phrases into active ones greatly clarify this sentence.

4. No.2
(Worse) A thorough review of linear estimation methods was made in their investigation so that the life data could be understood.
(Better) Their investigation thoroughly reviewed linear estimation methods to understand the life data.

5. No.3
(Worse) Comprehension of the maximum likelihood method is difficult for engineers with limited statistical training.
(Better) Engineers with limited statistical training have difficulty in comprehending the maximum likelihood method.

6. No.4
(Worse) Computational simplicity of linear estimation methods compared with MLE methods is apparent.
(Better) Linear estimation methods appear to be computationally simpler than MLE ones.

7. No.5
(Worse) Consideration of the interaction and variability of variables is not made by the conventional approach.
(Better) The conventional approach does not consider the interaction and variability of variables.

8. [Note 3.10]
To increase word variety in a sentence, evaluate and assess can be used instead of always saying consider when the Chinese meaning is 考慮.

9. No.6
(Worse) Identification and assessment of several models is possible.
(Better) Several models can be identified and assessed.

10. No.7
(Worse) Promulgation and verification of the accreditation standards is impossible.
(Better) The accreditation standards can not be promulgated or verified.

11. No.8
(Worse) This cycle is continued with until fluctuation of the selected model stops.
(Better) This cycle continues until the selected model stops fluctuating.

12. No.9
(Worse) An evaluation of their adequacy can be made with the proposed scheme.
(Better) The proposed scheme can evaluate their adequacy.

13. No.10
(Worse) Reduction of the task complexity is achieved by application of the nonparametric technique to industrial settings.
(Better) Applying the nonparametric technique to industrial settings reduces the task complexity.

14. No.11
(Worse) Only those factors having significant effects on the response average are identified by the proposed procedure so that unreplicated experiments can be interpreted.
(Better) The proposed procedure identifies only those factors that significantly affect the response average to interpret unreplicated experiments.

15. No.12
(Worse) Selection is made of the optimal levels by experienced engineers for the factors having significant effects on the response average and standard deviation.
(Better) Experienced engineers select the optimal levels for the factors significantly affecting the response average and standard deviation.

16. No.13
(Worse) A serious limitation on the effectiveness of the current system is caused by user demand.
(Better) User demand seriously limits the current system's effectiveness.

17. No.14
(Worse) Creation of new genes is possible by innovative technologists.
(Better) Innovative technologists can create new genes.

18. No.15
(Worse) The requirement that ID cards must be shown by students when entering the library is stipulated by school policy.
(Better) School policy requires that students show their ID cards when entering the library.

19. [Note 3.11]
Depending on the sentence‘s context, requires and stipulates can be used as alternatives to needs when the Chinese meaning is 需要.