全國公共英語考試語法—— 時態(tài)一致

1) 如果從句所敘述的為真理或不變的事實，則永遠(yuǎn)用現(xiàn)在時。
    At that time, people did not know that the earth moves.
    He told me last week that he is eighteen.
     2) 賓語從句中的助動詞ought, need, must, dare 時態(tài)是不變的。
    He thought that I need not tell you the truth.