1.It is two years ＿I joined the army.A.before B.since C.that D.after2.It was two years＿I joined the army.A.before B.since C.that D.after老师说的是第一题选B,第二题选A.他没讲清楚,没搞懂.这两个句子到底是怎么回事啊,

Question

1.It is two years ＿I joined the army.A.before B.since C.that D.after
2.It was two years＿I joined the army.
A.before B.since C.that D.after
老师说的是第一题选B,第二题选A.他没讲清楚,没搞懂.
这两个句子到底是怎么回事啊,为什么不能用that?

Answer 1

第一句,到现在为止我已经参军两年了
第二句应该是在我参军前的两年（同LS）
如果是强调句才用that
但强调句去掉it is（was）……that 要是完整的句子,明显这两句都不是