Ben ___ _ breakfast every day. [ ]
A. have to
B. has to
C. has to have
D. has to has
答案:C
金属的柔软性好,则表示其塑性好。
血小板在止血中功能包括()
A.活化因子Ⅻ,启动内源凝血途径
B.粘附功能
C.聚集功能
D.释放功能
E.收缩功能