用一般过去时代替完成时1） 两个动作如按顺序发生，又不强调先后，或用then，and，but 等连词时，多用一般过去时。When she saw the mouse，she screamed.My aun
现在进行时现在进行时的基本用法：a. 表示现在（ 指说话人说话时） 正在发生的事情。We are waiting for you.b. 习惯进行：表示长期的或重复性的动作，说
be to和be going tobe to 表示客观安排或受人指示而做某事。be going to 表示主观的打算或计划。I am to play football tomorrow afternoon.（客观安排）I’m going to play foo
be going to / will用于条件句时，be going to 表将来，will 表意愿例句：If you are going to make a journey, you’d better get ready for it as soon as possible.Now if you will take off y
regret doing/to doregret to do 对要做的事遗憾。 （未做）regret doing 对做过的事遗憾、后悔。 （已做）I regret to have to do this, but I have no choice.我很遗憾
In 1971, after Einstein’s death, two scientists were able to carry out a crucial experiment. They used two atomic clocks, synchronized them, and placed one on a plane, while the other stayed in the
The experiment was replicated in 1996 with advanced technology, and it was proved again--with an even bigger time difference proves that not only is time “warp-able”, but Einstein was arguably the
If it were possible, however, it would present some pretty knotty paradoxes... For example, what if someone or something traveled back in time ensuing future? And have you heard the one about the time
公共英语二级考试：语法讲解汇总1公共英语二级考试：语法讲解（1）2公共英语二级考试：语法讲解（2）3公共英语二级考试：语法讲解（3）4公共英语
感官动词 + doing/to do感官动词 see, watch, observe, notice, look at, hear, listen to, smell, taste, feel + do 表示动作的完整性，真实性；+doing 表示动作的连续性，进行