机器的输出功率总是()输入功率。
A.大于
B.小于
C.大于和等于
D.小于和等于
参考答案:B
用回弹法测定强度,测量碳化深度值时,用浓度为( )%的酚酞酒精溶液滴在孔洞内壁的边缘处。
A.1
B.2
C.3
D.4
—___________ they like salad?
—No, they ___________. [ ]
A. Do; don't
B. Does; does
C. Do; do
D. Does; don't