They have________signs in some places to remind (提醒)the visitors not to step on the grass.
________ our great joy, it never rained during the trip.
On no account ________ to our plan for the picnic.
Unfortunately, when I arrived she ________, so we had only time for a few words.
_______ two exams to worry about, I have to work really hard this weekend.
The tickets are________ for 5 days only.