Do you think K-12 students can learn as much in an online course as they can in a traditional class? please give me some ideas...

It honestly depends on the person. Some people learn better in a traditional class and some people do better online. Sometimes it better to be in traditional class because you can ask a question and the teachers can help you then, whereas online teachers will have to get back to you when they can. At the same time, online classes doesn't let you do any projects with people as you would in a traditional.

in the following paragraph, the fourth sentence the correct answer is: three personal subject pronouns

”she was embarrassed when she found that they had been put back on the shelves…”

a   subject pronoun is a personal pronoun. i, you, he, she it, we, they.  

in the sentence it can be observed she, used twice and they used once. is for this reason that is a three personal subject pronoun sentence.