【问】 The letter which I mailed to my sister a month before Christmas has notyet reachedto her. (EPT)
 答案为D(把reached to her改为reached her)。但是reach to同样也作“到达”解，为什么不能用reach to呢?请看下面的例句：
 He'll fit an extension so that the flex can reach(to) the socket. (ODCIE)
 他将安装一个线板，以使电线能够接到插座上。
 上例说明，reach与reach to是可以互换的。
 【答】 reach与reach to主要有两个区别。
 A.reach to一般只与表示处所的名词(代词)连用，而作“到达”解的reach则没有这个限制。
 例如：
 1. We had twenty miles to walk to reach the nearest railway station. (Davies)
 我们得走20英里才能到达最近的火车站。
 2. Your letter never reached me.(UED)
 你的信从未到达我手。
 3. Not a sound reached our ears. (ALD)
 没有一点儿声音传到我们耳朵里来。
 B. reach to着重过程，而reach+直接宾语则强调完成意义，表示目标已达到。请看下面的实例：
 1. The rope won't reach to the ground so you'll have to jump the last few feet.
 绳子伸不到地面，因此到最后几英尺你得跳下去。
 2. Your voice won't reach to the back of the auditorium; we'll have to use an amplifier.
 礼堂后排听不到你的声音，还是要用一下扩音器。
 3. I like curtains that reach to the floor.
 我喜欢一直拖到地板上的窗帘。
 4. He wore a coat that reached to his knees. (Wood)
 他穿着一件长到膝盖的大衣。