We can’t go to the concert. _____, it’s too cold.Besides, we’ve no tickets.

It is uncertain ________ side effect the medicine will bring about, although about two thousandpatients have taken it.[ ]

Do you know when they ________—________ a winter morning.

ately, what the witness reported tothe police on the phone led to ___________

Beihai Park is one of __________ parks in Beijing.