【单选题】The teacher was a little angry because the students didn't _____ their exercise books on time. [ ]
【单选题】The students didn't stop talking _______ the teacher came in. [ ]
【简答题】在图示轮系中,已知:蜗杆为单头且右旋,转速 ,转动方向如图示,其余各轮齿数为 ,试: (1)说明轮系属于何种类型; (2)计算齿轮4的转速 ; (3)在图中标出齿轮4的转动方向。
【单选题】关于灰色色彩运用的说法错误的是
A.
浅灰色富有朦胧感 ,用于女装有高贵典雅的效果
B.
暗灰色与皮肤色的颜色有较大的明度差,适用面较小
C.
灰色的服装有正式感,因此人们喜欢把各种灰色作为职业服的首选
D.
灰颜色的衣服还耐脏污,所以在一般的劳动防护服中,灰色占有优势地位
【单选题】关键词的每条回复,最多可设置( )个汉字
【单选题】The students didn't stop _____until the teacher entered the classroom
【单选题】The students didn't find much ___ about the topic on that website.