肉用仔鸡的生产有何特点？
参考答案：
饲养周期短，饲料报酬高，出肉率高，肉质好，成本低，利润大。
More highways have been built in China, _______it much easier for people to travel from one place to
another.[ ]
A. making
B. made
C. to make
D. having made
对作物群体结构及物质生产的环境影响因素主要指（）。
A、光照
B、温度
C、水分
D、肥料
E、CO2
