*He is a hard-working but not very intelligent boy. 他是个用功但不是很聪明的孩子。 *It is cold in winter here, but it is not hot in summer. 这里冬天很冷，但是夏天不热。 *His first response was to say no. Later, however, he changed his mind. 他最初的反应是不同意，可是后来他改变了主意。 *You should always strive to achieve more, however well you have done before. 不管以前做得多么好，你应该始终争取更大的进步。