Mass concentration
[化] 質(zhì)量濃度
?? 詞語組成解析
mass
[m?s]
n. 大量，大多;塊，堆，團;[物理學(xué)]質(zhì)量;彌撒曲;
vt.& vi. （使）集中，聚集;
adj. 群眾的;大規(guī)模的;整個的;集中的;
vi. 聚集起來;
vt. 使集合;
??? 情景例句
They don't ask how much someone paid for something.
他們不問別人買某個東西要花多少錢。
Would you please have these clothes washed for me?
可以請你為我把這些衣服洗了？
In fact a basic amount of movement occurs during sleep which is specifically concerned with preventing muscle inactivity.
事實上，睡眠狀態(tài)下仍有著基本的活動量，以防止肌肉活動停止。