—Bruce,how many students are there in your school?

—Mmm, about            .

A．two thousands

B．two thousands of

C．two thousand of

D．two thousand

A、B、C分别是NaOH、NaCl和H₂SO₄中的一种溶液，将无色酚酞试液滴入B溶液，B溶液显红色，将此红色溶液少量加到A中仍显红色，则A、B、C依次是[ ]

A．NaCl、NaOH、H₂SO₄

B．H₂SO₄、NaOH、NaCl

C．NaOH、H₂SO₄、NaCl

D．NaOH、NaCl、H₂SO₄