Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.
The purpose of a labour union is to improve the working conditions, ______, and pay of its members.
A. jobs are secure
B. to be secure
C. the job’s security
D. job security
Đáp án : D
Cụm từ: job security: an toàn trong công việc