Google Classroom. Unfortunately, there isn't a "read receipt" type of feature built into Google Classroom. That doesn't mean all hope is lost for determining whether or not students recognize that they have assignments or announcements to read in Google Classroom. Here's what I've been doing and recommending to friends and colleagues who ask.
To make sure that my students are acknowledging that they have new assignments and announcements in Google Classroom I've been sending out group emails that simply say, "You have a new assignment, please check Google Classroom. Please let me know that you've read this email." But I don't leave it at that. Before I send out the email I make sure that I've enabled "request read receipt" in the message settings. The screenshot below shows you where that option is found. By having read receipt enabled I can see if a student has opened the email even if he or she doesn't actually reply to me.
If you don't see the Read Receipt option in your G Suite for Education account, ask your domain administrator if he or she can turn it on. Domain administrators can turn it on for all users or for individual users.
On a related note, my video on how to create contact groups in Gmail is embedded below.