题目

如图所示为再生能力很强的原生动物喇叭虫(图中a.纤毛；b.大核；c.根部)，将之切成①②③三截，其中能再生成喇叭虫的部分是 A . ①②③ B . ③ C . ② D . ① 答案：C—Hi, Johnson, any idea where Susan is?—It’s class time, so she _____ in the classroom now.A. can be B. must have beenC. might have been D. should be