超声心动图检查时,划分次大面积肺血栓栓塞症的依据是()
A.肺动脉扩张
B.右心室局部运动幅度降低
C.室间隔左移和运动异常
D.三尖瓣返流
E.右心室和右心房扩大
参考答案:B
Paul isn’t as ______ as Sandy. He often makes mistakes in his homework.
A.careless
B.more careful
C.more careless
D.careful
数据6、8、9、8、10、8、9、6的平均数为______,众数是______,中位数是______.