长沙连续五届科技成果转化交易会的主题都是？
参考答案：
产学研金一体化科技创业在长沙。
It took him three hours to ________ all the homework. [ ]
A. finishes doing
B. finish doing
C. finished did
D. finished do
SAS硬盘的数据传输速度可以达到（）。
A、300MB/s
B、3.0GB/s
C、500MB/s
D、5.0GB/s
