21.It has long been known that there is an electric field ______.
a. inside the earth b. inside earth c. inside an earth d. on earth
22.______ much harder work, the volunteers were able to place the raging forest fire______.
a. By the means of…under the control b. By means of…under control
c.By means of…under a control d. By a means of…under control
23.No sooner had the man departed than the tree began dropping coffee beans ______.
a. by the thousand b. by a thousand c. by thousands d. by thousand
24.He expressed ______ of their having ever been married.
a. the doubt b. a doubt c. doubt d. an doubt
25.He saw through the little boy’s tricks ______.
a. at glance b. at the glance c. at some glance d. at a glance
26.Their victory is ______,for they’ve lost too many men.
a. out of question b. out of the question c. out question d. of question
27.Many a girl wants to become ______.
a. some secretary b. a secretary c. secretary d. secretaries
28.He grabbed me ______ and pulled me onto the bus.
a. a arm b. an arm c. the arm d. by the arm
29.I’ll come in ______ minute; in fact I’ll come ______ moment I’m through.
a./…the b. a…the c. the…a d. /…/
30.This is one of ______ interesting books on your subject.
a. the most b. the most of the c. most d. most of the