31000用科学记数法表示为( )
A.31×103
B.3.1×103
C.3.1×104
D.0.31×105
将31000用科学记数法表示为:3.1×104.
故选:C.
The young man couldn't afford a new car. ________, he bought a used one. [ ]
A. Besides
B. Otherwise
C. Instead
D. Still
泌尿系结石( )
A.常见于高脂肪餐后B.起病急骤,病情迅速恶化C.高热,全腹压痛肌紧张D.腹部绞痛,伴有血尿E.剑突下疼痛伴有恶心呕吐