What are these ______ English? [ ]
A. on
B. in
C. to
D. with
答案:B
John felt when he heard the result.[ ]
A. discouraging; discouraged
B. discouraged; discouraging
C. discouraging; discouraging
D. discouraged; discouraged
线段AB=2cm,延长AB到C,使BC=AB,再延长BA到D,使BD=2AB,则线段BD的长为______cm.