Peter, where did you guys go for the summer vacation?—We ____ busy with our work for months, so we went to the beach to relax ourselves

It is essential that these applicationforms ______ back as early as possible.

The museum was___opened this morning and some officials attended the opening ceremony(开幕式)

Is Tom still smoking? — NoBy next Saturday he ______ for a whole month without smoking a single cigarette

During the summer holiday， some students will plan to go to Dalian by _______ sea and camp by _______ sea.