1) be +现在分词,构成进行时态,例如: They are having a meeting. 他们正在开会。 English is becoming more and more important. 英语现在越来越重要。 2) be + 过去分词,构成被动语态,例如: The window was broken by Tom.. 窗户是汤姆打碎的。 English is tau...