问题
选择题
Don’t interrupt me. I ________ letters all morning and have only finished five.
A．write
B．have written
C．have been writing
D．am writing
答案
答案：C
考查时态。句意：别打扰我，我一上午都在写信，到现在才写好五封。现在完成时表示从过去某一时间开始的动作一直到现在还在继续。