正常人的脉搏在每分钟().
A、50-70次
B、60-100次
C、70-100次
D、90-120次
参考答案:B
It _______ we had stayed together for a couple of weeks _______ I found we had a lot in common.[ ]
A. was until; when
B. was until; that
C. wasn’t until; when
D. wasn’t until; that
筛管输导的物质和输送的方向是( )
A.有机物从上向下
B.有机物从下向上
C.无机盐和水从上向下
D.无机盐和水从下向上