她的角色直到第二幕才出场。

Her character doesn't appear until ___Act 2.

一切进展顺利，直到我们演到“阳台那幕戏”。

Everything was going all right, until we reached the "balcony ___act".

第一幕很搞笑，但第二幕却很悲伤。

The first ___act was funny, but the second act was sad.