1·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.
而且如果这样的监控将被视为可选监控，我方相信其选择权也不是承包商的而是业主或者其代表的。
4·Abundant optional colors the entire table, and exercise a sense of clear-cut, it tells you, the original life can be so colorful.
整个表可选颜色丰富，并且运动感鲜明，它告诉您，原来生活可以如此多彩缤纷。
5·Some things shouldn't be optional - and for too many of us, they are. For example; intelligent eating, structured and regular exercise and healthy lifestyle.
有些东西是强制性的，但更多的东西并不是，比如科学饮食，坚持、系统地锻炼，保持健康等等。