根据所给汉语提示完成句子。

1. It's hard for the old villagers _____ (谋生) in big cities.

2. They stayed at home _____ (一直) because of the heavy rain,

3. The boy practiced basketball very hard _____ (为了) become a professional basketball player.

4. Many athletes _____ (捐钱给慈善机构) to help poor people.

5. If you don't work hard now, you'll never _____ (上大学).

诊断用超声的波长范围是

A．0.015～0.15mm

B．0.15～1.5mm

C．1.5～15mm

D．0.15～1.5cm

E．1.5～15cm