1.Which identifiers are valid?
a) _xpoints
b) r2d2
c) bBb$
d) set-flow
e) thisisCrazy
I choose b,c,e ,but supply my answer to website,it
show error
2.If you want subclasses to access, but not to override a superclass member method, what keyword should precede the name of the superclass method?
fill the keyword:
I fill "super",but failed
3. For what reasons might a
thread stop execution?
a) A thread with higher priority began execution.
b) The thread's wait() method was invoked.
c) The thread invoked its yield() method.
d) The thread's pause() method was invoked.
e) The thread's sleep() method was invoked.
I choose a,c but failed
4. Which of the following describe the sequence of method calls that result in a component being redrawn?
a) invoke paint() directly
b) invoke update which calls paint()
c) invoke repaint() which invokes update(), which in turn invokes paint()
d) invoke repaint() which invokes paint directly
I choose a,d but failed
Who can tell me the correct answer,and why?
thanks