工人在邮件室手动分拣信件。

Workers perform ___manual sorting of letters in the mailroom.

她试图通过手动按压关节来缓解我膝盖的疼痛。

She tried to cure the pain in my knee by putting ___manual pressure on the joint.

它既有手动功能也有自动功能，因此有很多可能性。

It has both ___manual and automatic functions so it has a lot of possibilities.