区别：has to be不得不是 has been 已经是 has been 已经 如： 1、She has been reunited with her natural mother. 她和亲生母亲团聚了。 2、The article has been finished. 文章写好了。 3、The system we introduced in 1980 has been a great improvement. 我们1980年引进的系统有了很大改进。 has to be 必须 如： 1、The operator has to be able to carry out routine mai
