AP News:美防长马蒂斯任内首度访华

1.His trip comes amid trade tensions and as the US and China work together to push for North Korea's denuclearization.

tension 紧张关系

Racial tensions exploded into riots.
种族间的紧张关系爆发成骚乱。

2.The American Civil Liberties Union says that would be illegal and violate the Constitution.

violate 违反

She violated the terms of the contract repeatedly.
她三番五次地违反合同条款。