Is it necessary to look up every new word when I come across it in reading?—No. You ________， because you are likely to guess the meaning from the context.

When did the new Wenfeng Shopping Mall open—It ________ for nearly half a year.

 ________are you going to do during your holidays－I’m going on a trip to Hainan.

Medical education and engineering education belong to totally different categories and are always on ________ tracks, it is difficult to develop cross-subjects between them.

It’s lucky _________ you ________ such a good teacher.