-Do you know why my flight has been delayed？ _ It is () bad weather conditions.
A. because
B. due to
C. owing to
D. because of
How should we go through the security check？
A. you should wait one by one
B. show your certificate only
C. put your carry _on baggage on the belt ,which will take it to be sereen bay X-ray equipment
D. you should go through the gate and the staff may give you a personal search
Even a person joins the crew, he has to go through the pre-boarding security screening procedures.
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