He ______ to swim when he was five. [ ]
A. can
B. could
C. can be able
D. was able
答案:D
下列以赔款金额为基础来计算分保责任限额的有()。
A.险位超赔再保险
B.事故超赔再保险
C.超额赔付率再保险
D.超额赔款再保险
双壁透照双面成像时,有效透照长度()。
A.与焦距成正比
B.与焦距成反比
C.与焦距基本无关
D.与工件直径无关