She’s upstairs ______ letters.
A. writes
B. is writing
C. write
D. writing
正确答案:D
18.答案为Dwritingaletter为现在介词短语在本句中作为伴随状语
She’s upstairs ______ letters.
A. writes
B. is writing
C. write
D. writing
正确答案:D
18.答案为Dwritingaletter为现在介词短语在本句中作为伴随状语