請(qǐng)用介詞since 或for填空：
（1）His grandfather has been dead

for

for

over five years．
（2）Mr．Smith has worked in this university

since

since

he came to China．
（3）My sister has had a heavy cold

for

for

three days．
（4）His uncle has been a member of the Party

since

since

about ten years ago．
（5）Her mother has been away from home

for

for

nine months．