1 . It is hard to say what kind of person he is. Sometimes he is very friendly; at other times he ___ be very cold.

A．can

B．must

C．will

D．shall

2 . It doesn’t often snow in my hometown in winter, but it ___be rather cold sometimes.

A．shall

B．should

C．can

D．would

3 . ----- Oh, my goodness! My laptop must have got stolen．
----- But where _____ a thief have entered the house with all the doors and windows still locked?

A．should

B．could

C．dare

D．did

4 . 23．—Artistic people_________be very difficult sometimes．
—Well，you should know you married one．

A．can

B．might

C．could

D．Must