A.NaHCO3.
B.Na2SO4.
C.NH4HCO3.
D.NaHSO4.

A.\(F\left( 2 \right) = \dfrac{\pi }{8}\)
B.\(F\left( 2 \right) = \dfrac{\pi }{2}\)
C.\(F\left( 2 \right) = \dfrac{\pi }{4}\)
D.\(F\left( 2 \right) = 0\)

A.\(\int {f\left( x \right)dx}  = \dfrac{{\arcsin x - x\sqrt {1 - {x^2}} }}{2} + C\)
B.\(\int {f\left( x \right)dx}  = \dfrac{{\arcsin x + x\sqrt {1 - {x^2}} }}{2} + C\)
C.\(\int {f\left( x \right)dx}  = \dfrac{{2\arcsin x - x\sqrt {1 - {x^2}} }}{2} + C\)
D.\(\int {f\left( x \right)dx}  = \dfrac{{2\arcsin x + x\sqrt {1 - {x^2}} }}{2} + C\)

A.\(F\left( t \right) =  - 9\cot t - \dfrac{{9{t^2}}}{2} + C\)
B.\(F\left( t \right) =  - 9\cot t - 9t + C\)
C.\(F\left( t \right) = \cot t + \dfrac{{{t^2}}}{2} + C\) 
D.\(F\left( t \right) =  - \cot t - t + C\)

A.knot
B.fort
C.spot
D.sport

A.at
B.of
C.to
D.on

A.situation
B.moment
C.event
D.case

A.that
B.which
C.what
D.why

A.conclusively
B.conclusive
C.conclude
D.conclusion

A.knot
B.fort
C.spot
D.sport