unsparing

1.be unsparing in one's efforts

不遗余力

2.an unsparing superior officer; unsparing criticism.

一名苛军官；不留情面批评

3.he is unsparing in his criticism of the arms trade.

他对军火交易进行无情批评。

4.she had won her mother's unsparing approval.

她赢得母亲慷慨赞许。