Congrats on launching EPractice's new site. I understand it is a beta launch and there's a lot to fix. That said, i like the UI. Registration was smooth and worked in Safari with third party stuff blocked. I like that you get the categories on which you scored well/poorly.
I found a number of errors though.
"beta til Sept 17, 2017" - Two year beta? A number of questions say "choose two" in the question and then right above the answer say "select any one of the given answer". The grammar is wrong and more importantly, the instructions conflictA number of questions say "Assume all necessary importing have done". This isn't good grammar#1 - Line 19 says to assume necessary imports. Imports can't be in the middle of a program#11 - In choice D, "If we chance the print method" should be "If we change the print method"#18 - It says which is inserted in line 12, but a line is there. Do you mean replace or to leave it blank?#20 - Line 10 prints the sum, but the line we fill in prints out directly rather than assigning to that variable#21 - I'm pretty sure no second answer. Supplier/Consumer have differnet method. Predicate returns bookean , not R. UnaryOperator doesn't have R#26 - Choices are about compilation failing at lines 11 and 13. Line 11 is } and there is no line 13#27 - "Which of the following functional interface" - should be interfaces