______ a language family is a group of languages with a common origin and similar vocabulary, grammar, and sound system.

A．What linguists call

B．It is called by linguists

C．Linguists call it

D．What do linguists call

读图，完成下列问题。

有关甲、乙、丙附近三个阴影区域比例尺大小的叙述，正确的是（）

A.甲处比例尺最小，丙处比例尺最大

B.甲、乙、丙处比例尺相同

C.甲处比例尺大于乙，乙处比例尺大于丙

D.乙处比例尺最小