题目内容：

    I’m sitting in my kitchen in London, trying to figure out a text message from my brother. He lives in our home country of Germany. We speak German to each other, a language that's rich in strange words, but I've never heard this one before: fremdschämen.

The experience gets me to consider: can we lose our mother language? Most immigrants (移民)know what it’s like to be not as good at their mother language as before. The process seems obvious: the longer you are away, the more your language suffers. But it’s not quite so straightforward. It turns out that how long you've been away doesn't always matter. Socializing with other native speakers abroad can worsen your own native skills. And emotional factors like trauma(精神创伤) can be the biggest factor of all.

In children, the phenomenon of language attrition (语言磨蚀)is somewhat easier to explain since their brains are generally more flexible and adaptable. Until the age of about 12, a person’s language skills are relatively easy to change. Studies on international adopters have found that even nine-year-olds can almost completely forget their first language when they are removed from their country of birth.

But in adults, the first language is unlikely to disappear entirely except in extreme circumstances. For example, Monika Schmid analyzed the German of elderly German-Jewish wartime refugees(难民) in the UK and the US. The main factor that influenced their language skills wasn't how long they had been abroad or how old they were when they left. It was how much trauma they had experienced as victims. Those who left Germany in the early days of Nazi occupation, before the worst violence, tended to speak better German – despite having been abroad the longest. Those who left later, tended to speak German with difficulty or not at all.

“It seemed very clearly a result of this trauma”, says Schmid. “Even though German was the language of childhood, home and family, it was also the language of painful memories”. The most traumatized refugees had held them back. As one of them said: “I feel that Germany betrayed me. America is my country, and English is my language.”

1.What does the first paragraph serve as?

A.A comment B.A background

C.An explanation D.An introduction

2.What do paragraph 4 and 5 mainly talk about?

A.How two languages coexist

B.The way to deal with adult’s trauma

C.The reasons behind adult’s language attrition.

D.Whether trauma leads to adult’s language attrition.

3.Why does trauma cause a person's mother language to disappear?

A.Because he can’t remember his mother language.

B.Because his ability to communicate is affected.

C.Because his country is far from him .

D.Because he chooses to escape from bad experiences.

4.What is the best title for the passage?

A.Where does your native language come from?

B.Will you lose your native language?

C.How does trauma affect your first language?

D.How far are you from your mother tongue