Some molecules are large enough ________ (see) under the electronic microscope.

Those who’d like to visit the exhibition ________ (sign) your names here.

Hefellasleepimmediatelylastnight;hemust________(be)verytired.

Ifound________toanswerallthequestionswithinthetimegiven.

This diploma ( 毕业文凭 ) ________ that you have completed high school.