下列各句中，划线的成语使用恰当的一项是（  ）

在方框中填入一个恰当的词、或填入所给单词的适当形式，使短文通顺、正确、连贯。
    A lot of people wish to be slim, but at the same time they are____（worry）about their health. In fact, it is important for everyone to lose weight healthily. A strong body can keep you working in a high speed and make you more positive every day. However, how can you do it? Here's some good____（advice）.
    ●Drink plenty of water and eat____healthy diet. If you feel like____（eat）snacks, drink a glass of water first. If you are still hungry after 15____（minute）, then it's time for a light snack. Try to stay away from food with high calories, such as sweets and fast food.
    ●Do not eat____(much) than you can consume (消耗). People get fat because they can’t consume all the calories ____they get. So, knowing how many calories you really need is very important.
    ●Take enough exercise.  The  “333” is good   for you—exercise three____(time) a week, for at least 30 minutes at a time, and your pulse rate (脉搏率) should be more than 130 after____(exercise).
    Keep the three pieces of advice in mind and follow the advice. Then you'll____(sure) have a slim and strong body.

将一株生长正常的绿色植物置于密闭的玻璃容器内，在适宜条件下光照培养，随培养时间的延长，玻璃容器内CO₂浓度可出现的变化趋势是（　　）

直角三角形有（   ）条高．

有三种液体，1号黏稠度最大，2号最重，3号颜色最深，则流动最慢的是____号液体。