过期妊娠下列哪项正确()
A.妊娠的时间越长胎儿体重越大
B.易发生胎儿窘迫
C.与孕激素水平过低有关
D.羊水量无明显变化
E.妊娠超过40周
参考答案:B
We arc supposed ______ school on time. [ ]
A.arrive
B.to arrive at
C.getting to
D.reaching
林业两大体系指()、()。