The slight change of weather can ______ her delicate health

We have ______ at 30 days ’ sight for the amount of the invoice.

Neither English nor Chinese ________ difficult to learn.

My aunt, whose absence was _____ for three weeks, was heartily welcome to remain away, for we were much merrier and more comfortable without her.

The house was quiet in the night, ________ the occasional coughing from my throat.