Which of the following words means an instrument for recording and measuring time?
A. watch
B. chromograph
C. chronometry
D. chronograph
查看答案
A polygon is a figure on a flat surface having ? straight sides.
A. one or two
B. two or three
C. three or four
D. five or more
At this medical school, the students attended pregnant women through delivery, providing () care for them and thie babies.
A. heterogeneous and homogeneous
B. eugenic and antenatal
C. anthropoid and philanthropic
D. prenatal and postnatal
聚氯乙烯(PVC)是一种( )。
A. 热固性塑料,可制造化工用排污管道
B. 热塑性塑料,可用作导线外皮绝缘材料
C. 合成橡胶,可制造轮胎
D. 热固性塑料,可制造雨衣、台布
酚醛塑料是( )。
A. 热固性塑料,可制造农用薄膜
B. 热塑性塑料,可制造农用薄膜
C. 热固性塑料,可制造插头、刀闸、内燃机曲轴皮带轮
D. 热塑性塑料,可制造仪表壳
微信支付 
支付宝支付