Hydrogen is the fundamental element of the universe ______ it provides the building blocks from which the other elements are produced.

A．so that

B．but that

C．in that

D．provided that

有效的自编测验应具有测验的可靠性，即多次测验分数的稳定、一致的程度。我们称之为测验的（）

A.效度

B.信度

C.难度

D.区分度