241. I wondered whether I …………. (lock) the door or not.
242. She says that she ……….. (live) in the country when she ……….. (be) a child.
243. The teacher said that the shortest distance between two points ……….. (be) a straight line.
244. They hoped that they ………… (end) soon.
245. When the teacher came in, the pupil ………. (play).
246. Columbus …………. (discover) America more than 400 years ago.
247. Yesterday, while I ……….. (write) a letter, the telephone ………. (ring).
248. Bill said he ………. (forget) to buy a new dictionary.
249. Kite and I ……….. (wait) right here until you ………… (get) back.
250. Helen regretted that she ………. (not can) go with us.

giải:

241. I wondered whether I lock (lock) the door or not.

242. She says that she lives (live) in the country when she is (be)a child.

243. The teacher said that the shortest distance between two points is (be)a straight line.

244. They hoped that they end (end) soon.

245. When the teacher came in, the pupils play(play).

246. Columbus discovers (discover) America more than 400 years ago.

247. Yesterday, while I write (write) a letter, the telephone ring (ring).

248. Bill said he forget (forget)to buy a new dictionary.

249. Kite and I wait (wait) right here until you get (get) back.

250. Helen regretted that she not can (not can) go with us.

241. Had locked

242.lived/was

243. Is

244.Would end

245.Were playing

246. Discovered

247.was writing/rang

248. Had forgotten

Học tốt ^^ 

Xin 5*, xin cảm ơn và CTLHN ạ :))