Thomas Alva Edison didn’t “invent” the light bulb (灯泡), but rather he ______ a 50 –year –old idea, which is not well –known.
| A．improved upon | B．take down | C．put up | D．break away |
The children ＿＿＿＿＿＿ very quiet； I wonder what they ＿＿＿＿up to.
| A．were； are being | B．are being； are |
| C．are； do | D．are being； do |
Jim talked for about half an hour yesterday.Never＿＿＿＿＿ him talk so much.
| A．I heard | B．did I hear |
| C．I had heard | D．had I heard |
——＿＿＿＿＿ Betty this morning?
—— Not yet, but she is sure to be here before noon.
| A．Have you seen | B．Will you see |
| C．Do you see | D．Did you see |
—— Are you a visitor here?
—— That’s right.I＿＿＿round the world and now my dream of coming to China＿＿＿true.
| A．have traveled； has come |
| B．was traveling； had been come |
| C．am traveling； has come |
| D．have traveled； has been come |
All but one＿＿＿＿take part in the conference＿＿＿＿tomorrow.
| A．is going to； that is to take place |
| B．are going to； that is about to take place |
| C．are going to； that is to be taken place |
| D．are going to； which is to be held |