单项选择题 下面描述数字信号和模拟信号的区别哪个正确？

单项选择题 词汇题Fill in the blanks in the following sentences with the words given below. Change the forms where necessary.Not all of the author's (____) for improving students' performance at school are logical.

不定项选择 Oliver Twist is believed to the most autobiographic one among Charles Dickens’ many literary works.