现在进行时：e.g. The new airport is being built by a foreign company. 一家外国公司正在承建这座新机场。 The song is being sung by the girls now. 过去进行时： e.g. The song was being sung by the girls when I got there. The student was being criticized when I went into the teacher’s office.

am/is/are + being +过去分词

was/were being+过去分词