It was in 1969 the American astronauts first succeeded in landing on the moon. A. thatB.

问题补充：

It was in 1969 the American astronauts first succeeded in landing on the moon.

A. that

B. when

C. which

D. in which

答案：

(答案→)A. that

B. when

C. which

D. in which

解析：考查强调句型。It is... that是强调句型，可以强调除谓语外的任何成分；去掉不影响句意。句意“美国宇航员成功登陆月球是在1969年。”本句强调的是时间状语in 1969。故选A。