If you check your pictures you will notice that hoverflies (like all flies) have only two wings (bees and wasps have four).
Then, furthermore, I think one can recognize kind of a 'white spot' on the back/side of the flies in some of your pictures. These reduced wings are called "halteres". Please check this image.
The eyes of hoverflies are huge, their antennae very short, and their proboscis looks different than the one of bees.
Concerning #6 I just made the effort to determine the exact species for you: it's a female Eristalis arbustorum (please check for example the pattern on its back).
I just want to understand ..@jaki01 Ok, I understand that you say bees have 4 wings, and hoverflies have 2 wings, but based on https://en.wikipedia.org/wiki/Western_honey_bee, this one has only 2 wings and I think this is the same one on my picture, isn't ? Or on my photos there are 4 wings that look like 2 wings ?
Are you all kidding me?? :)
Where in your link is stated that bees would have only two wings??? Citation, please!
... and it has FOUR! Do you really want to tell a biologist whose father is a beekeeper how many wings bees have?
Did you read my discussion with @barski? It seems it causes huge problems for inexperienced insect photographers to differentiate between bees and hoverflies. I wasn't aware of this problem before I created this community.
As you obviously don't believe me, just read here.
Of course it isn't the same!
Did you check the pattern on the back of the fly in your picture and compare it with the photo in the link which I gave you, yes or no? If I give you a link, please check that link.
Why in the end I always must show you the pictures because you just don't open the links??
Eristalis arbustorum, CC BY-SA 4.0, Source.
You said "Are you all kidding me??"
Not at all ! ... I know you are an expert on insects and me not at all , I just wanted to understand a little bit more on differences. I looked the links you gave me, but it is not easy at all when we are not familiar on biology.
But I took note of your advices :-)
Just found this new post on hoverflies : https://peakd.com/hive-101587/@dannewton/insect-portrait-project-hoverflies
Don't worry, I guess determining insect species is not easy for you, but can you imagine that it's really very time- and energy-consuming for me to discuss every second day with various users the differences between bees, wasps and hoverflies? :-)
Did you also see the triangle-shaped pattern on the back of your #6 and compared it with the photo I showed you?Did you for example read the link concerning the number of wings in bees? It's four, and your hoverflies have only two. That alone is enough to exclude the option it could be a bee. Then the post from @dannewton shows a haltere very well, right?
I hope all that helped you a little bit.