This book is well worth _______. Would you like to buy one?
| A．to read | B．being read | C．reading | D．to be read |
26．The researehers delermine what type of plants the virus can infect(感染) and____insects can carry the virus.
| A．those | B．why | C．which | D．How |
25．—Did you get my letter?
—I received one just as I____.
| A．set out | B．had set out | C．was setting out | D．would set out |
24．When she called at his studio, she____that he had gone to Japan.
| A．is told | B．was told | C．tells | D．Told |
23．Robert made a call to his parents yesterday afternoon. To his disappointment, ____of them answered it.
| A．either | B．both | C．none | D．Neither |
22．I_____stop by sometime and thank her for all her help.
| A．must | B．would | C．could | D．May |