在车门、车厢没有关好时不要驾驶机动车起步。
参考答案:对
若函数f(x)在R上的图象关于原点对称,x∈[0,+∞)时,f(x)=x(1-x),则x∈(-∞,0]时f(x)=( )
A.x(x+1)
B.-x(1+x)
C.-x(1-x)
D.x(x-1)
________ trees have been planted near here, so the air is very fresh.[ ]
A. Two hundreds
B. Hundred of
C. Hundreds of
D. Hundreds