be going to 常用于事先经过的打算、 计划或意图, 也可用于根据某种迹象将要发生的动作
Why are you taking down all the pictures?I am going to repaint the wall.
L ook at the dark clouds in the sky. I t ‘ s going to rain.
will 常用于不受人的主观意愿影响的单纯将来, 也可用于条件状语从句中
还可以表趋向或习惯的动作。 如:Tomorrow will be Teacher ‘ s Day.
I f it doesn ‘ t rain tomorrow, we will go to the zoo.W e will die without air or water.
Half of class won ‘ t comehalf, adj and n. 一半(的)
half常用于名词或修饰名词的冠词前面 , 即half a/an/the/one ‘ s +n.
还可以用于 a half +n. 这中结构。 如:P lease cut the cake into halves.