糊墙织物( ) A．17 B．18 C．19 D．20
参考答案：C—59050000
-How often does he write emails to his friend?-______.
A．Once a month
B．In a week
C．For half an hour
D．Last Monday
镗削不通孔时，镗刀的主偏角应取（）。
A、45°
B、60°
C、75°
D、90°
