大腿假肢的长度和健侧比较()。
A.可比健侧长1cm
B.可比健侧长2cm
C.要求两侧一样长
D.可比健侧短1cm
E.可比健侧短2cm
参考答案:D
The fact has worried many scientists _____ the earth is becoming warmer and warmer these years.
A.which
B.that
C.as
D.what
人类在进化过程中最显著的变化是学会使用工具.______.