在我国，引起咯血的首要原因（）
A.肺炎
B.肺脓肿
C.肺结核
D.肺梗死
E.肺寄生虫病
参考答案：C
She _____ this book for nearly three weeks. [ ]
A. has borrowed
B. has lent
C. has bought
D. has kept
有哪些因素影响晶体成长速率？
