because引导的原因状语从句用将来时吗

题目

because引导的原因状语从句用将来时吗
再问一个,Baby tigers learn to catch other animals if they ()their mother A see B look at C watch D look for

答案

原因状语从句
要点:由连词because,since,as引导,也可由for,now that 等词引导
1.I didn’t go to school yesterday because I was ill.
我昨天没去上学,因为我生病了.
2.Since everybody is here,let’s begin our meeting.
既然大家都来了,让我们开始开会吧.
3.As you are in poor health,you should not stay up late.
既然你身体不好,你就不该熬夜.
4.I asked her to stay to tea,for I had something to tell her.
我请她留下来喝茶,因为我有事要告诉她.
.难点——because ,since ,as ,for,辨析
1） because语势最强,用来说明人所不知的原因,回答why提出的问题.当原因是显而易见的或已为人们所知,就用as或 since.
I didn’t go,because I was afraid.
Since /As the weather is so bad,we have to delay our journey.
2） 由because引导的从句如果放在句末,且前面有逗 号,则可以用for来代替.但如果不是说明直接原因,而是多种情况加以推断,就只能用for.
He is absent today,becaus e / for he is ill.
He must be ill,for he is absent today.