Decide which of the choices given below would correctly complete the passage if inserted in the corresponding blanks. Mark the correct choice for each blank.

Television makes ___1___ possible for us to see a distant scene as a transmitter at the television studio telecasts the scene to our___2___. But by means of radar, the outlins of distant objects are shown on the viewing screen on the receiver, even though there is no distant transmitter to telecast the ___3___. Perhaps what is even more ___4___than that is radar's ability to "see" in the ___5___or through heavy clouds. The pilot in an airplane___6___with radar, ___7__at night, can see on the radar viewing screen distant buildings, or perhaps a ___8___mountain peak that is miles ahead.
Radar can thus be used to guide airplans through ___9___to their destinations. During war, it enables bombers to find their targets at night or through___10___ clouds. Ground radar sets can “see ” enemy planes at great distances through darkness or clouds, and can direct antiaircraft to fire at them. Battleshio radar sets permit accurate night bombardment of enemy ships or shore installations.
1.a. that        b. this       c. that        d.it
2.a.receiver     b. receive    c. sender      d. send
3.a. spot       b. view      c.scene        d. outlook
4.a. remark     b. mark      c. to mark     d.remarkable
5.a. day        b. daytime   c.dark         d. darkness
6.a.equipped    b. equip     c. to equip      d. equipment
7.a.fly         b. to fly      c. being flying  d.flying
8.a. danger     b. dangerous  c. more danger  d.most danger
9.a.darkness    b.dark       c. light        d. bright 
10. a.big       b. thick      c.heavy        d. small
Key: 1.d  2.a   3.c  4.d  5.c  6.a  7.d  8.b  9. a  10.c