钢拱架应全部被喷射混凝土覆盖，保护层厚度不得小于()。
A.20mm
B.30mm
C.40mm
D.50mm
参考答案：C
如图表示蛙的发育过程，正确的发育顺序是（ ）
A．②→③→④→⑤→①
B．④→②→③→⑤→①
C．③→②→④→⑤→①
D．①→⑤→④→②→③
In that month, he earned as much as, if ____ than, $40 000.
A．no more
B．not more
C．no much
D．not much
