干燥器更换干燥剂后,要使干燥剂填实,同时应保证出气滤网到缸头的距离在()范围内。
A、64±2
B、65±2
C、65±1
D、64±1
参考答案:B
____ catch the first bus, she got up earlier that morning.
A.In order to
B.So as to
C.In order that
D.So that
首选用哪项检查来协助作出诊断
A.急诊胃镜检查
B.血清淀粉酶
C.B型超声
D.腹部平片