Với f(x)=x2-1x2+1 tập nghiệm của pt f'(x)=0 là:
A. ∅.
B. R.
C. {0}.
D. Một kết quả khác.

Find a mistake in the four underlined parts of the sentence and correct it:
If you have already decided on a course that you would like to study at university, or we recommend that you take a look at the course requirements first.
A. have already decided
B. that
C. or we
D. first

Find a mistake in the four underlined parts of the sentence and correct it:
We all know that we have to work hardly to earn a living ourselves and support the family.
A. that
B. hardly
C. ourselves
D. and support

Find a mistake in the four underlined parts of the sentence and correct it:
Next Sunday I'll have to visit the dentist again, that I detest.
A. I'll
B. to visit
C. that
D. detest

Find a mistake in the four underlined parts of the sentence and correct it:
The shopkeeper warned the boys don’t lean their bicycles against his windows.
A. The
B. don’t
C. their
D. against

Find a mistake in the four underlined parts of the sentence and correct it:
I always talk to my parents before make an important decision.
                                                                                
A. talk to
B. parents
C. make
D. decision.

Find a mistake in the four underlined parts of the sentence and correct it:
This dish tastes like it has meat in it. but it consists with vegetables.
A. This
B. like
C. in it
D. with

Find a mistake in the four underlined parts of the sentence and correct it:
You really may stop worrying about your brother.
A. really
B. may
C. worrying
D. about

Find a mistake in the four underlined parts of the sentence and correct it:
I know a small restaurant at where you can get a wonderful meal.
A. know
B. at where
C. can get
D. wonderful

Find a mistake in the four underlined parts of the sentence and correct it:
Electricity is the most critical energy for the future of many countries and cheap, plentiful electricity is associated for high employment and productivity.
A. the most
B. plentiful
C. for
D. and productivity