trả 100 xu ------------------ III. CHOOSE THE WORD OR PHRASE THAT BEST FITS THE BLANK SPACE. Bell and his assistant, Thomas Watson, (1)_ many experiments and (2) came up with a device which they first introduced in 1876. Bell said (3) the telephone: "Mr.Watson, come here. I want you." This was the first telephone Traveling all over America, Bell (5) his invention to the public at countless exhibitions and by 1877 the first telephone was in (6) use. 1. a. gave b. took c. conducted d. made 2. a. final b. finally c. firstly d. secondly 3. a. in b. on c. at d. with 4. a. saying b. speech c. message d. speaking 5. a. demonstrated b. showed c. gave d. performed 6. a. commerce b. buying c. selling d. commercial