Over four years of work experience in the trade and some courses in floor covering installation are usually required to be eligible for trade certification.
或者通常需要超过四年的行业工作经验，以及一些地板覆盖安装课程，才有资格申请行业认证。
2
A combination of over three years of work experience in the trade and some college or industry courses in welding is usually required to be eligible for trade certification.
或者要取得行业资格认证，通常需要三年以上的行业工作经验，以及学习一些大学或工科课程的焊接课程。
3
A combination of over four years of work experience in the trade and some college or industry courses in heating systems installation and repair is usually required for trade certification.