感染人的疟原虫有下列几种（）
A.三日疟原虫
B.间日疟原虫
C.不规则疟原虫
D.卵形疟原虫
E.恶性疟原虫
参考答案：A, B, D, E
The book is rather highly priced, but so well worth ______ that it should be begged or borrowed rather than missed.
A．to read
B．to be read
C．reading
D．being read
