1 . If someone happens to have high fever and pneumonia, he or she _________ seek treatment fast.

A．must

B．needs

C．may

D．could

2 . Timmy, why        in the mud? I have already told you so many times not to!

A．must you sit

B．should you sit

C．will you sit

D．can you sit

3 . Just as I was hurrying to class, there ________ come Tom with a long story to tell you.

A．could

B．must

C．might

D．would

4 . Public health experts kept telling citizens it was of utmost importance that social distancing and hygiene habits ________ amid the pandemic.

A．were to be kept	B．had to be kept
C．must be kept	D．should be kept