-- What was Jim wearing at the party?

-- Nothing ________. He was in his usual shirt and jeans.

A．special

B．simple

C．important

D．interesting

单斗挖掘机按其驱动动力不同，可分为（）

A、电力挖掘机和柴油挖掘机

B、液压传动和机械传动

C、履带式挖掘机与轮胎式挖掘机

D、轮斗挖掘机和索斗铲