He didn't go home _______ he finished his homework. [ ]
A. when
B. if
C. until
D. that
答案:C
合金是指由两种或两种以上的元素(其中至少一种是金属元素)组成的具有金属特性的物质。
HS-SICH作为上行信令信道,承载()以及()信息。