依次填入下列各句横线处的成语，最恰当的一组是（ ）①中央出台八项规定和厉行节约反对浪费的系列举措以来，社会公众响应号召，作为党员的老张更是身体立行，食不二味， 。②倘若自己的安全和切身利益受到威胁，但凡是正常的人，都会 ，必会前奔后忙，严防死守，彻去危情方能心安。③在群众路线的实践中，有的干部把“深入”变为“身入”， 就匆匆离开，被广大网友痛批为作秀，造成了恶劣的影响。

With the rapid development of medical science, we ______ more new drugs used in the treatment of cancer.

Could you please come to the museum with me this afternoon—Sorry, I ______ . I have to take a piano lesson at 2 pm.

Your city looks beautiful.—Yes. Lots of trees and grass ________ last year.

What was your brother like when he was young— He _______ be quiet, but now he’s very outgoing.