A（）is a type of bar chart that illustrates a project schedule.It illustrates the start and finish dates of the terminal elements and summary elements of a project.

A.Gantt chart

B.project histogram

C.milestone chart

D.project flowchart

髁突经咽侧位片与许勒位片比较，在显示髁突骨质病变方面下述那种说法是正确的？

A．髁突经咽侧位片比许勒位更能清楚显示髁突骨质病变

B．二种片位在显示髁突骨质病变方面基本相同

C．许勒位片比髁突经咽侧位片能更清楚地显示髁突骨质病变

D．许勒位片和髁突经咽侧位片都不能清楚地显示髁突骨质病变