英语完形填空解释

题目

英语完形填空解释
When you turn the phone on it tries to find a signal.This signal comes from the telephone network.Usually,if the signal is weak,_1_ can be difficult to make a phone call.（（When the phone is finding a signal,it also sends a message to the telephone network.））If you have s signal you can see it on the phone's screen.This message tells the station where the phone is.
1.选项有A.it B.you
但是B也能说得通啊!
2.还有打括号的句子中的it指的是“手机”还是“信号”?

答案

介个...
it can be是可能的意思吧,这里的it我认为指的是手机信号弱的情况,it's adj.to do是一个句型,表示做什么事怎么样...
意会意会哈T.T
括号里的it指的是手机