nvm~it worked out~thank u so much~ ^^

That is your problem. 1B03 must be taken before 1BA3/1BB3.... also, I don't think you can take BOTH 1BA3 and 1BB3. They are the same course, with one as a "Physics" track, the other a "Life Sci" track. You choose which one you think is more appropriate for you. They cover the same material, with one having a slightly more "math" focus.

**Edit: Took me a while with the window open before actually replying. I see you've taken care of it already!