根据以下木材的截面尺寸,指出小方为()。
A.10mm³50mm;
B.30mm³100mm;
C.30mm³30mm;
D.80mm³80mm。
参考答案:C
We do not need to wait in line for hours for a ticket this year because we can use the website or hotline to ________ tickets and then pick them up at railway stations or ticket agencies.
A.release
B.relieve
C.reserve
D.review
根据公式H=FXb/a,以下叙述错误的是
A.H表示几何模糊B.F表示焦点尺寸C.b表示焦-片距D.a表示焦-肢距E.H=0.2mm为模糊阈值