18.--- Tom has a lot of parties recently.---Yes, that may ____ why he didn’t do well in the test.A, sum up B. add up to C. account for D. make sense of
It’s a common sense _____ Canberra, _____ between Sydney and Melbourne, is the capital of Australia.
– I wonder how much you charge for your services. -- The first two are free________the third costs $30.
--Would you please explain to me about the difference between the two phenomenon? --I’m sorry, but that’s just _____ I’m puzzled about.