OECD制定了()。
A、国际种子检验规程
B、ISO9000系列标准
C、国际植物新品种保护公约
D、种子认证方案
参考答案:D
I learned from my book that it was nothing but ten years of hard work that ______ his success in business.
A.led to
B.looked up
C.referred to
D.got through
板式楼梯由踏步板、斜梁和平台板、平台梁组成。