下列句子中，哪一句使用了被动语态？
Mark Twain wrote the book.
Mark Twain is writing the book.
The book is on the table.
The book was written by Mark Twain.
选择正确的被动语态句子。
The cake is delicious.
The children are eating the cake.
The cake was eaten by the children.
The children ate the cake.
哪一句是被动语态？
The letter is on the desk.
John sent the letter.
John is sending the letter.
The letter was sent by John.
选择正确的被动语态句子。
The workers are building the house.
The workers built the house.
The house is beautiful.
The house was built by the workers.
下列句子中，哪一句使用了被动语态？
Steven Spielberg is directing the movie.
Steven Spielberg directed the movie.
The movie was directed by Steven Spielberg.
The movie is interesting.
选择正确的被动语态句子。
The choir is singing the song.
The song was sung by the choir.
The song is popular.
The choir sang the song.
在被动语态中，主语是动作的执行者。
被动语态的基本结构是 'be + 过去分词'。
被动语态不能用于现在进行时。
在被动语态中，动作的承受者成为句子的主语。