Some people get in touch with each other by mobile phones__________ others keep contact with each other by e-mail.
| A．when | B．before | C．while | D．since |
16．Large quantities ofinformafion，as well as methnely help，_______since the organization was built．
A has offered B．had been omred
C．have been offered D．is offered
15．A large____of money is spent on the Hope Project and a good inany schools____step．
A amount：has been B amount：have been
C．number；has been D deal；have been
14．The nunther of the students who took part in the competition____500，but only a small number of them chosen。
A was；were B were；was C．were；were D．w；was
13．About 90 percent of the equipment presented by the administration，as well as the facilities of our own， ______made good use of in teaching．
| A．have | B．has | C．have been | D．has been |
12．______of the land in that district_____covered withtrees and grass.
A．Two-fifth；is B．Two-fifth；are C Two-fifths；is D Two-fifths；are