Sleeping is a popular way to relax______students．（　　）

A．onB．amongC．aboutD．between

Did you call Jenny？

Oh no，I forgot．I_____her right away．（　　）

A．calledB．have called

C．callD．will call

Water is important to______，so there are many water festivals around the world．（　　）

A．everyoneB．nobodyC．somebodyD．something

Now all Chinese couples______to have two children．（　　）

A．allowB．allowed

C．are allowedD．were allowed

Students_______enjoy the colorful school life if they study at home instead of going to school．（　　）

A．mustn'tB．can'tC．mustD．can