22．His suggestion is that ______ action be taken to improve ______ situation．
| A．/; the | B．an; the | C．I; a． | D．the;a |
Our classroom is very clean. Do you know who＿＿＿cleaned it?
| A．was it that | B．it was that | C．was it who | D．he was |
—— Was that the new comer who walked by?
—— ＿＿＿＿＿.
| A．It must be that | B．It must have been | C．He must be | D．This must have been |
＿＿＿＿being March 12th, they planted trees on the hill.
| A．That | B．It is | C．It | D．This |
—— Have you ever seen a whale alive?
—— Yes, I’ve seen ＿＿＿.
| A．that | B．it | C．such | D．one |
＿＿＿＿four years since I joined the army.
| A．There was | B．There is | C．It was | D．It is |