本期内容：

Bernie Sanders provided the biggest surprise so far in America’s presidential primaries, narrowly beating Hillary Clinton in Michigan’s Democratic contest on Tuesday. Mrs Clinton, who trounced Mr Sanders in Mississippi the same day, remains on course to take the party’s nomination. On the Republican side Donald Trump recorded big wins in both states. Marco Rubio put in another dismal showing.

词义解析:

Trounce：完胜
On course: 按照既定路线
Dismal：差劲的