在下列实验中,盛氧气的集气瓶里应该预先装少量水或铺一层细砂的是( ) A.硫黄燃

题型:选择题

问题:

在下列实验中,盛氧气的集气瓶里应该预先装少量水或铺一层细砂的是(  )

A.硫黄燃烧

B.铁丝燃烧

C.蜡烛燃烧

D.木炭燃烧

考点:氧气的性质
题型:选择题

一个长方体的长、宽、高都扩大2倍,它的表面积就______.

题型:选择题

下列句子中,没有语病的一项是[ ]

A.省政府组织多个督查组到各地督办“地沟油”严打情况,共取缔无证照食用油经营户33户、非正规来源食用油33738公斤。

B.据了解,建设完成后,荔湖新城项目将起到提升新城区防洪、排涝能力,完善荔城中心城区城市配套功能,提升城市品位。

C.广州楼市还是相当平稳的,基本没有出现退房潮,也没有其他城市的因为楼盘大幅降价而产生的业主打砸售楼处的事件。

D.不仅紫心番薯纤维含量较高,有助于促进胃肠蠕动,改善消化道环境,而且含有丰富的微量元素,能够提高人体的免疫能力。

题型:选择题

Play is very important for humans from birth to death. Play is not meant to be just for children. It is a form of (1) that can tap into your creativity, and can allow you the chance to find your inner child and the inner child of others. I have collected the (2) of play here.
Play can stimulate you (3) . It can go against all the rules, and change the same (4) . Walt Disney was devoted to play, and his willingness to (5) changed the world of entertainment. The next time you are stuck in a (6) way of life, puI1 out a box of color pencils, modeling clay, glue and scissors, and (7) and break free. You will be amazed at the way your thinking (8) .
Playing can bring greater joy into your life. What do you think the world would be like if (9) each day in play I bet just asking you this question has (10) . Play creates laughter, joy, entertainment, (11) . Starting today, try to get 30 minutes each day to engage in some form of play, and (12) rise!
Play is known (13) . Studies show that, as humans, play is part of our nature. We have the need to play because it is instinctive and (14) . With regular play, our problem-solving and (15) will be in much better shape to handle this complex world, and we are much more likely to choose (16) as they arise. It creates laughter and freedom that can instantly reduce stress and (17) to our daily living.
Play can (18) , curiosity, and creativity. Research shows that play is both a "hands-on" and "minds-on" learning process. It produces a deeper, (19) of the world and its possibilities. We begin giving meaning to life through story making, and playing out (20) .

题型:选择题

当苷类成分为药物有效成分时,一般不用下列哪种辅料处理()

A.酒

B.醋

C.麦麸

D.滑石粉

E.甘草汁

题型:选择题

《中国药典》(2010年版)采用HPLC法测定硫酸庆大霉素C组分时用的检测器是 ( )

A.折光检测器

B.紫外检测器

C.质谱检测器

D.蒸发光散射检测器

E.二极管阵列检测器

更多题库