This completes the optional portion of this exercise.
这个练习的可选部分也完成了。
2
As far as I am concerned the use of stored procedures, database triggers and foreign key restraints is OPTIONAL, not MANDATORY, therefore I am free to exercise my option not to use them.
这样的话，我认为存储过程，触发器，外键是可选的，而不是强迫的，因此我可以自由的选择不去用它们。
3
Furthermore if such surveys are considered optional surveys then we believe the right to exercise the option is not left to the contractor, but to the Employer or his representatives.