配制10000mL某注射液,调成等渗(该注射液的冰点下降度为0.05℃),需加氯化钠()
A.100g
B.90g
C.87g
D.80g
E.81g
参考答案:E
29. It is known to us that doing eye exercises ________ our eyes, and that is to say, our eyes can ________ doing eye exercises.
A.benefits; benefit from
B.benefits to; benefit
C.benefits from; benefit
D.benefits; be benfited from
用化学方程式回答下列问题:
(1)胃酸过多时可服用胃舒平(含有氢氧化铝)来减轻症状______.
(2)可以用稀盐酸来清洗长期盛放石灰水的试剂瓶______.
(3)可以用稀硫酸来清除铁锈______.