七鳃鳗的幼体被称为（）。
A、柱头虫
B、沙隐虫
C、短腕幼虫
D、鳗虫
参考答案：B
I got close enough to hear them speaking Chinese, and I said "Ni Hao,"just as I________do in China.[ ]
A. must
B. might
C. can
D. should
可以同时删除字符前导和尾部空白的函数是 ______。
A．Ltrim
B．Rtrim
C．Trim
D．Mid
