Question

Susan will not arrive at the airport on time _____she hurries up．
A．once          B．if                C．unless

Answer 1

C

考查連詞。once 一旦，if 如果，unless除非，句意：蘇姍不會(huì)按時(shí)到達(dá)機(jī)場(chǎng)除非她快點(diǎn)。所以選C。