I didn't _____________ that! [ ]
A. know
B. knew
C. known
答案:A
When insects feed on decaying plant material in a compost pile, they help turn it into useful garden soil.
A.available
B.organic
C.distasteful
D.decomposing
在“测定某种食物中的能量”的探兖实验中,小明提出的问题是“花生仁与核桃仁哪个含能量多?”在他制定的计划中不正确的是[ ]
A.在锥形瓶内加入同样多的水,并插入温度计
B.实验前安装好实验装置,并测量水温
C.取一个花生仁和一个核桃仁作为实验材料,燃烧后比较水温升高的差异
D.重复实验3次,取平均值进行比较