把40克的盐放入200克的水里,这个盐水的含盐率约是百分之几?
40÷(200+40)×100%,
=40÷240×100%,
≈17%.
答:这个盐水的含盐率约是17%.
—I'm ______ to eat a horse now!
—Really? But I don't have ______ for you. It's a great pity! [ ]
A. hungry enough; food enough
B. enough hungry; enough food
C. hungry enough; food enough
D. hungry enough; enough food
护士在给病人进行静脉注射时,常用橡胶管扎紧上臂,此时,扎结处的静脉就会积血膨大、突起。这种积血膨胀现象主要表明[ ]
A.静脉内血流从近心端流向远心端
B.静脉位置较浅
C.静脉管腔大,管壁弹性大
D.静脉内有瓣膜