题目

A person _____e-mail account is full won’t be able to send or receive any e-mails．A．whoB．whom C．whoseD．whoever 答案：C3a2-5a+1与-2a2-3a-4的和为( )A. 5a2-2a-3 B. a2-8a-3 C. -a2-3a-5 D. a2-8a+5