不属于系统故障的是( )。
A. CPU故障
B. 操作系统故障
C. 磁头故障
D. 突然停电
在HAc溶液中,加入少量NaCl晶体,溶液的 pH将会 ( )
A. 升高
B. 降低
C. 不变
D. 无法判断
精密度高的测定结果其准确度一定高。
A. 对
B. 错
Answer the questions according to the text.1. Why is it possible that you might buy the red, green and yellow peppers even though they are not on your shopping list?They look so __1___ . And they're on __2___ .