问题补充:
Process has been very smooth. , we are not confident that it will be completed on time.
A. Therefore
B. Besides
C. Though
D. However
答案:
A. Therefore
B. Besides
C. Though
(答案→)D. However
解析:考察副词辨析。A因此;B而且;C否则,要不然;D然而;句意:过程很顺利,然而,我们很不自信会不会准时完成。根据句意说明D正确。