5 – Complete with may, can, could, must, mustn’t, should, shouldn’t.<br />
a. We _______________ reduce air pollution. (obligation)<br />
b. My sister _____________ swim very well. (ability/present)<br />
c. You _________________ smoke here. (prohibition)<br />
d. ________________ I come in? (permission/formal)<br />
e. You _________________ go to that restaurant. The food is delicious! (advice).<br />
f. You __________________ eat too much. You’re getting fat! (advice)<br />
g. She __________________ play tennis very well some years ago. (past ability)<br />
h. _________________ you open the window, please? (very formal permission)<br />​