选择（为什么选它）和翻译：
问题描述：
选择（为什么选它）和翻译：
Ten days (). long enough for Mr.Carter to finish his design. He doesn't need any more.
A is
B has been
C was
D had been
答
A
表示一段时间,用第三人称单数形式.全句为一般现在时,所以选A.