题目

下列有关细胞中元素和化合物的叙述，正确的是（ ） A . 碳是构成细胞的基本元素，生物大分子以碳链为骨架 B . 动物体内的能源物质只有脂肪和糖原 C . 氨基酸脱水缩合产生水，水中的氢只来自氨基酸的氨基 D . RNA和DNA组成元素的种类不同，碱基种类也不同 答案：A(根据句意，从方框中选择恰当的单词填空，注意大小写和词形变化) 　　and , work , about , take , excuse , sale 1. I like music. How ___________ you, Linda? 2. ___________ me. Are you Mr White from America? 3. My brother often ___________ a shower at seven o’clock. 4. Oh, look at those green shorts. They are on ___________ for just \$25! 5. The basketball game is Oct. 10th ___________ the school trip is Oct. 25th. 6. My father usually goes to ___________ at eight o’clock in the morning.