首次检定的流量计要查看说明书中流量计出厂K系数，周检的流量计不需查看前几次检定证书中的K系数。（）
参考答案：错
One of the most inportant questions they had to consider was ____ of public health. [ ]
A. that
B. this
C. that
D. which
为什么目前主要是用农药来防治病虫害？
